Explanation / Rationale

Considering:

• Usability testing is in Q3 (1 – C)
• Component testing is in Q1 (2 – A)
• Functional testing is in Q2 (3 – B)
• Reliability testing is in Q4 (4 – D)

Thus:
a) Is correct
b) Is not correct
c) Is not correct
d) Is not correct

Explanation / Rationale

a) Is not correct. The approval of the budget is an example of an entry criterion. It would make no sense to approve the budget for some activity that has already been done
b) Is correct. Running out of budget can be viewed as a valid exit criterion
c) Is not correct. Availability of resources is an example of an entry criterion for testing
d) Correct. Coverage is a measure of thoroughness, so it is a typical exit criterion
e) Is not correct. This is an example of an entry criterion, checked before the project starts

Explanation / Rationale

a) Is not correct. The paragraph contains information on test levels and exit criteria, which are part of the test approach
b) Is not correct. The paragraph contains information on test levels and exit criteria, which are part of the test approach
c) Is not correct. The paragraph contains information on test levels and exit criteria, which are part of the test approach
d) Is correct. The paragraph contains information on test levels and exit criteria, which are part of the test approach

Explanation / Rationale

Considering each of the listed tool categories:

i. Collaboration tools – facilitate communication. Communication does not include the facilitation of test execution
ii. DevOps tools - support the DevOps delivery pipeline, workflow tracking, automated build process(es) and CI/CD. The delivery pipeline and CI/CD both include the facilitation of test execution, such as component testing for CI
iii. Management tools – increase the test process efficiency by facilitating management of the SDLC, requirements, tests, defects and configuration. The management of these items does not include the facilitation of test execution
iv. Non-functional testing tools – allow the tester to perform non-functional testing that is difficult or impossible to perform manually. Non-functional testing can include both static testing and dynamic testing, including test execution
v. Test design and implementation tools – facilitate generation of test cases, test data and test procedures. The generation of this testware does not include the facilitation of test execution

Thus:
a) Is not correct
b) Is correct. Both DevOps tools (ii) and Non-functional testing tools (iv) facilitate test execution
c) Is not correct
d) Is not correct

Explanation / Rationale

a) Is not correct. The test pyramid emphasizes having a larger number of tests at the lower test levels
b) Is correct. It is not true that near the top of pyramid, test automation should be more formal
c) Is not correct. Usually component testing and component integration testing are automated using API-based tools
d) Is not correct. For system testing and acceptance testing, the automated tests are typically created using GUI-based tools

Explanation / Rationale

a) Is not correct. A member without a missed deadline can get a discount and a gift T-Shirt after 15 bicycle rentals
b) Is not correct. A member without a missed deadline can get a discount but no gift T-Shirt until they rented a bicycle 15 times
c) Is not correct. Non-members cannot get a discount, even if they did not miss a deadline yet
d) Is correct. No discount as a non-member that has also missed a deadline, but only members can receive a gift T-Shirt. Hence, the action is not correct

Explanation / Rationale

a) Is not correct. Strong communication skills, active listening, and teamwork abilities enable a tester to interact effectively with all stakeholders, however a deep knowledge of a variety of computer games that allowed them to get on well with one developer is not an example of a generic skill useful to testers
b) Is correct. Domain knowledge that can be used to understand and communicate with end-users and business representatives is one of the generic skills required by testers. A tester with experience as a pilot would make them better able to appreciate the acceptance criteria for the helicopter control system
c) Is not correct. Although programming skills could be considered as technical knowledge which can increase efficiency when utilizing some test tools, it is unlikely that these skills would improve their communication with business analysts
d) Is not correct. Although thoroughness, attention to detail, curiosity, and a methodical approach to identifying hard-to-find defects are all useful generic skills for testers, it is doubtful they would be generating test cases prior to starting exploratory testing. This is because one of the main tenets of exploratory testing is that the test cases are generated during the testing, not scripted in advance

Explanation / Rationale

a) Is not correct. Testers should review work products as soon as drafts are available to enable early testing as part of a shift-left approach. If they waited until the next development phase, then unnecessary development (and test) work could be started on unreviewed, flawed work products
b) Is correct. Testers should review work products as soon as drafts are available to enable early testing as part of a shift-left approach
c) Is not correct. Testers typically review work products that form the test basis as part of test analysis, not before test analysis and design
d) Is not correct. Testers should review work products as soon as drafts are available to enable early testing as part of a shift-left approach. Waiting until they are published means that any defects that could be found by tester review will be in the published document

Explanation / Rationale

Considering each of the listed test activities and their output testware:

A. Test analysis - prioritized test conditions (4) (e.g., acceptance criteria), and defect reports for defects identified in the test basis
B. Test design - prioritized test cases, test charters, coverage items (1), test data requirements, and test environment requirements
C. Test implementation - test procedures, automated test scripts, test suites, test data, test execution schedule (3), and test environment elements such as stubs, drivers, simulators, and service virtualizations
D. Test completion - test completion report, documented lessons learned, action items for improvement, and change requests (2) (as product backlog items)

Thus:
a) Is correct. The correct match is: 1B, 2D, 3C, 4A
b) Is not correct
c) Is not correct
d) Is not correct

Explanation / Rationale

a) Is not correct. The organization’s marketing team is unlikely to perform much testing (although in some organizations they may be involved with acceptance testing), so their average level of experience (most of which would be in marketing) is not likely to impact how testing is performed for a given test object
b) Is not correct. The level of knowledge of users that a new system is being built for them is unlikely to affect how testing is performed. Any user involvement that could affect how testing is performed is more likely to be as a result of decisions made by the testers, customer and project manager
c) Is correct. The number of years’ experience of the members of the performance testing team will help to determine the capabilities and knowledge (e.g., of different tools and defect types) that the team members will apply when they are testing
d) Is not correct. The organizational structure of the different end users (who may be varied) will change between users. So, it may not even be known when the application is being tested, and the end user’s organizational structure can thus have little effect on how the testing is performed

Explanation / Rationale

a) Is not correct. Tracking test progress and identifying areas that require further attention is an example of supporting the ongoing control of testing. This is one of the purposes of test reports
b) Is not correct. Providing information on the tests executed, their results, and any issues or defects found is an example of summarizing the test activities performed at a given test level. This is one of the purposes of test reports
c) Is correct. Providing information about defects is the purpose of a defect report, not a test report
d) Is not correct. Providing information on testing planned for the next period is one of the purposes of test reports

Explanation / Rationale

a) Is not correct. Test monitoring involves the ongoing checking of all activities and comparison of actual progress against the test plan. Test control involves taking the actions necessary to meet the test objectives of the test plan. No test data are prepared during these activities
b) Is not correct. Test analysis includes analyzing the test basis to identify test conditions and prioritize them. Test design includes elaborating the test conditions into test cases and other testware. Test data are not prepared during these activities
c) Is correct. Test implementation includes creating or acquiring the testware necessary for test execution (e.g., test data)
d) Is not correct. Test completion activities occur at project milestones (e.g., release, end of iteration, test level completion), so it is too late for preparing test data

Explanation / Rationale

Considering each of the listed risks and their mitigations:

1. Long system responses (1) can be tested in performance testing (B)
2. Changes of consumers’ preferences (2) are usually out of our control, so usually we accept this risk (A)
3. Flooding of the server room (3) can cause significant loss, so we should transfer the risk, e.g., by buying an insurance policy (D)
4. That patients above a certain age receive inaccurate reports (4) suggests a potential boundary problem, which can be effectively detected with techniques like BVA (C)

Thus:
a) Is not correct
b) Is not correct
c) Is correct. The correct combinations of risk and mitigation are: 1B, 2A, 3D and 4C
d) Is not correct

Explanation / Rationale

a) Is not correct. It is impossible to prove that there are no defects anymore in the system under test. See testing principle 1
b) Is not correct. See testing principle 7
c) Is correct. Testing finds defects and failures which reduces the level of risk and at the same time gives more confidence in the quality level of the test object
d) Is not correct. It is impossible to test all combinations of inputs (see testing principle 2)

Explanation / Rationale

a) Is not correct. The feedback is from stakeholders (e.g., business representative, end user), not from developers, so this feedback is not likely to inform managers which developers are more or less productive
b) Is not correct. Early and frequent feedback from stakeholders is not used by project managers to prioritize how they interact with the different stakeholders
c) Is correct. Obtaining feedback from stakeholders early and often in the software development process can be highly beneficial as it facilitates early communication of potential quality issues, can prevent misunderstandings about requirements, and ensures that any changes in stakeholder requirements are understood and implemented sooner
d) Is not correct. Early and frequent feedback can prevent the development of a product that does not meet stakeholder needs, and results in costly rework and missed deadlines, so, ideally there should be no delay. Also, the feedback is from stakeholders (not to them), which includes the end users, so the end users providing feedback will not aid the end users’ understanding

Explanation / Rationale

a) Is correct. The primary benefit of independence in testing is that testers are more likely to identify different types of failures and defects compared to developers, due to their varied backgrounds, technical viewpoints, and potential biases, including cognitive bias. However, the main disadvantage of independence in testing is that testers may become isolated from the development team, leading to communication problems, a lack of collaboration, and potentially an adversarial relationship, with testers being blamed for delays and bottlenecks in the release process
b) Is not correct. A developer’s familiarity with the code does not mean that they rarely find defects in it, instead this familiarity means they can efficiently find many defects in their own code. And, rather than developers and testers having a shared background, developers having a different background to testers is normally cited as the reason that testers and developers find different kinds of defects
c) Is not correct. Testing can be conducted at different levels of independence, ranging from no independence for the author to very high independence for testers from outside the organization. In most projects, multiple levels of independence are utilized, with developers performing component and component integration testing, the test team performing system and system integration testing, and business representatives performing acceptance testing. So, testers can be in the developer’s team and do not need to come from outside the organization. Knowledge of the application domain will change from case-to-case and is not dependent on the level of independence
d) Is not correct. Testing can be conducted at different levels of independence, ranging from no independence for the author to very high independence for testers from outside the organization, with testers from outside the developer’s team generally more independent than testers from within the team. However, there is more reason to believe that testers from outside the team are likely to be more isolated from the developers and so are more likely to be blamed for delays in product release

Explanation / Rationale

a) Is not correct. Regression tests increase in number as the project progresses, as new regression tests are typically required as changes are made to the system. Similarly, the number of confirmation tests also typically increases as the project progresses as new confirmation tests are needed for each fix made to a system
b) Is not correct. It is the other way round. Confirmation tests are created and run when the test object is fixed, and regression tests are (ideally) run whenever the test object is enhanced (changed)
c) Is not correct. Confirmation testing verifies that a defect has been fixed correctly and so is concerned with testing changes to the test object. However, regression testing ensures that changes (including changes to the operational environment) do not have negative effects on unchanged software and so does not check that the operational environment remains unchanged
d) Is correct. Regression testing ensures that changes do not have negative effects on unchanged software. Confirmation testing verifies that a defect has been fixed – and so is concerned with changed code

Explanation / Rationale

a) Is correct. Test-Driven Development (TDD) is a well-known example of a test-first approach to development
b) Is not correct. Coverage-Driven Development is not a correct example of a test-first approach to development
c) Is not correct. Quality-Driven Development is not a correct example of a test-first approach to development
d) Is not correct. Feature-Driven Development is not an example of a test-first approach to development, but is, instead, an agile software development methodology based around delivering features (as opposed to user stories in Scrum)

Explanation / Rationale

a) Is not correct. A lack of usability provided through the user interface can be detected through a review using a suitable checklist, but the lack of usability can also be identified by getting several typical users to dynamically test the user interface and provide feedback on its usability
b) Is correct. A code review can detect code that cannot be reached by any path, however dynamic tests can only exercise reachable code and cannot determine that code cannot be reached without running every possible combination of inputs and input states, which is impractical for real code
c) Is not correct. Poor response times for most of the expected users are difficult to determine without executing the code (i.e., by static testing), so in this situation dynamic testing could find a defect, but static testing is unlikely to find it
d) Is not correct. A review of the code by someone who is aware of the required features could detect that the required features had not been implemented in the code, and dynamic testing could also be used to determine that these required features had not been implemented

Explanation / Rationale

a) Is not correct. Performing the impact analysis will not give information about completeness of tests. Analyzing the impact analysis of changes will help to select the right test cases for execution
b) Is not correct. Traceability does not give information about the estimated level of residual risk if the test cases are not traced back to risks
c) Is correct. Performing the impact analysis of the changes helps in selecting the test cases for the regression test
d) Is not correct. Analyzing the traceability between the test basis, test objects and test cases does not help in selecting test data to achieve the assumed coverage of the test object. Selecting test data is more related to test analysis and test implementation, not traceability

Explanation / Rationale

Considering each of the listed test activities and their tasks:

A. Test analysis - To identify the features that require testing, the test basis is analyzed and defined as test conditions, which are then prioritized along with related risks. During this test analysis, defects in the test basis are typically uncovered, and the test object's testability may also be assessed. (Task 4)
B. Test design - Involves using test conditions to create test cases and other necessary testware, such as test data requirements and test charters for exploratory testing. (Task 1)
C. Test implementation - Test procedures, such as manual and automated test scripts, are created from test cases and may be assembled into test suites. Test procedures are prioritized and arranged in a test execution schedule. (Task 3)
D. Test completion - Occurs at project milestones, such as release, end of iteration or end of test level. Testware is identified and archived or handed to the appropriate teams for reuse, the test environment is shut down, and the test activities are analyzed for lessons learned and future improvements. (Task 2)

Thus:
a) Is not correct
b) Is correct. The CORRECT match is: 1B, 2D, 3C, 4A
c) Is not correct
d) Is not correct

Explanation / Rationale

a) Is not correct. The fundamental strength of white-box test techniques is that the entire software implementation is taken into account during testing
b) Is not correct. White-box coverage measures provide an objective measure of coverage and provide the necessary information to allow additional tests to be generated to increase this coverage
c) Is not correct. White-box test techniques can be used to perform reviews (static testing)
d) Is correct. This is the weakness of the white-box test techniques. They are not able to identify the missing implementation, because they are based solely on the test object structure, not on the requirements specification

Explanation / Rationale

a) Is not correct. Acceptance criteria are the conditions used to decide whether the user story is ready. They cannot show work progress
b) Is not correct. Defect reports inform about the defects. They do not show work progress
c) Is not correct. Test completion report can be created after the iteration is finished, so it will not show the progress continuously within an iteration
d) Is correct. Burndown charts are a graphical representation of work left to do versus time remaining. They are updated daily, so they can continuously show the work progress

Explanation / Rationale

a) Is not correct. To ensure successful reviews, it's important to secure management's support for the review process, however that does not mean that they should participate as reviewers
b) Is correct. To ensure successful reviews, it's important to break the work product into parts that are small enough to be reviewed in a reasonable timescale to prevent reviewers from losing focus during individual review or review meetings
c) Is not correct. To ensure successful reviews, it's important to clearly define objectives and measurable exit criteria, without evaluating participants
d) Is not correct. To ensure successful reviews, it's important to break down the review into smaller chunks to prevent reviewers from losing focus during individual review or review meetings. So you should not plan to cover one document per review

Explanation / Rationale

Considering each of the listed review types:

1. Technical review - This type of review is performed by technically qualified reviewers and led by a moderator. The objectives are to gain consensus and make decisions on technical problems while also evaluating quality and building confidence in the work product, generating new ideas, motivating and enabling authors to improve, and detecting anomalies
2. Informal review - The main objective is to detect anomalies. The process is not defined and does not require formal documented output
3. Inspection - This is the most formal review type, and it follows the complete generic review process. The primary objective is to find the most anomalies, and other objectives include evaluating quality and building confidence in the work product, motivating and enabling authors to improve, and collecting metrics that can be used to enhance the software development life cycle (SDLC), including the inspection process. The author cannot act as the review leader or scribe
4. Walkthrough - Led by the author, this type of review serves various objectives such as evaluating quality and building confidence in the work product, educating reviewers, gaining consensus, generating new ideas, motivating and enabling authors to improve, and detecting anomalies. Reviewers might perform an individual review before the walkthrough, but this is not mandatory

A. Includes objectives such as gaining consensus, generating new ideas, and motivating authors to improve (A)
B. The main objective is detecting potential defects and it generates no formal documented output (D)
C. The main objective is detecting potential defects and it requires metrics collection to support process improvement (C)
D. Includes objectives such as educating reviewers, gaining consensus, generating new ideas and detecting potential defects (B)

Thus:
a) Is not correct
b) Is correct. The correct match is: 1A, 2D, 3C, 4B
c) Is not correct
d) Is not correct

Explanation / Rationale

Considering each of the listed example defects:

i. Two different parts of the design specification disagree due to the complexity of the design – this is an example of a specification defect, which includes inconsistencies, ambiguities, contradictions, omissions, inaccuracies, and duplications, which can most easily be found by static testing
ii. A response time is too long and so makes users lose patience – this is an example of a response time defect, which can only be detected in practice by executing the program and measuring the response time, which can most easily be found by dynamic testing
iii. A path in the code cannot be reached during execution - this is an example of a coding defect, which includes variables with undefined values, undeclared variables, duplicated or unreachable code, and excessive code complexity, which can most easily be found by static testing
iv. A variable is declared but never subsequently used in the program - this is an example of a coding defect, which includes variables with undefined values, undeclared variables, duplicated or unreachable code, and excessive code complexity, which can most easily be found by static testing
v. The amount of memory needed by the program to generate a report is too high – this is an example of a performance defect, which can only be detected in practice by executing the program and measuring the memory used, which can most easily be found by dynamic testing

Thus:
a) Is not correct
b) Is not correct
c) Is not correct
d) Is correct. The correct match for static testing is i, iii, and iv

Explanation / Rationale

The ‘exhaustive testing is impossible’ principle is concerned with the fact that it is not feasible to test every possible variation of test inputs in all different circumstances, except in trivial cases. Instead, testing utilizes test techniques, test case prioritization, and risk-based testing to sample from the set of possibilities and focus testing efforts.
a) Is not correct. The principle states that it is not feasible to test everything except in trivial cases. Testing everything would require testing every possible variation of test inputs in all different circumstances, which is generally infeasible as there will be a practically infinite number. Testing every possible specified output will not address this problem as the relationship between inputs and specified outputs can be different for each test object. Sometimes there may be a practically infinite number of possible specified outputs (e.g., when there are several variables representing real numbers), whereas at other times there may be just two specified outputs, such as with a single variable that can be either true or false
b) Is not correct. The principle states that it is not feasible to test every possible variation of test inputs in all different circumstances. This is because for non-trivial systems there is a practically infinite number. Therefore, in practice, documenting all possible test input variations would be impractical as it would take an infinite length of time
c) Is not correct. Starting testing as early as possible with reviews and other static testing approaches will not address the problem of there being too many possible test cases. The ‘early testing saves time and money’ principle is concerned with fixing defects early on to prevent the occurrence of subsequent defects in derived work products, thereby reducing costs and the likelihood of failures
d) Is correct. The use of equivalence partitioning and boundary value analysis to generate test cases is one way to address the principle as these test techniques provide a systematic way to derive a finite subset of all possible test cases

Explanation / Rationale

a) Is not correct. QA concentrates on process improvement and implementation, using a preventive approach to avoid errors and defects, while testing is a form of QC that is used to detect defects
b) Is correct. QC aims to achieve appropriate levels of quality by focusing on identifying and correcting product defects. Testing is a significant part of QC and helps to uncover these defects
c) Is not correct. Although testing is a significant part of QC and helps to uncover defects, other (non-testing) techniques utilized in QC include formal methods like model checking and proof of correctness, as well as simulation and prototyping
d) Is not correct. QA concentrates on process improvement and implementation, using a preventive approach to avoid errors and defects, while testing is a form of QC that is used to detect defects

Explanation / Rationale

a) Is not correct. The root cause is the distraction that the programmer experienced while programming
b) Is not correct. Accepting invalid inputs is a failure
c) Is not correct. The error is the mistaken thinking that resulted in putting the defect in the code
d) Is correct. The problem in the code is a defect

Explanation / Rationale

a) Is not correct. We do not accept the risk; concrete actions are proposed
b) Is not correct. No contingency plans are proposed
c) Is correct. The proposed actions are related to testing, which is a form of risk mitigation
d) Is not correct. Risk is not transferred but mitigated

Explanation / Rationale

The domain for the password length has three equivalence partitions:

• passwords too short {0, 1, …, 4, 5}
• passwords OK {6, 7, …, 11, 12}
• passwords too long {13, 14, …}

To achieve full coverage for 3-value BVA we need to test the following values:

0, 1, 4, 5, 6, 7, 11, 12, 13, 14.

Since 2-value BVA is already covered, this means that we have already tested the passwords of length:

0, 5, 6, 12 and 13.

This means that the additional lengths that need to be covered to move from 2-value to 3-value are:

1, 4, 7, 11 and 14.

Thus:
a) Is not correct
b) Is not correct
c) Is not correct
d) Is correct

Explanation / Rationale

a) Is not correct. Most work products can be examined using some form of static testing, and a contract must be interpretable by humans and so could be reviewed, which is a form of static testing
b) Is not correct. Most work products can be examined using some form of static testing, and a test plan must be interpretable by humans and so could be reviewed, which is a form of static testing
c) Is correct. Most work products can be examined using some form of static testing; however it is not suitable for work products that are too complex for human interpretation and should not be analyzed by tools, and encrypted code is too complex for humans and if it is properly encrypted it will not be analyzable by most tools
d) Is not correct. Most work products can be examined using some form of static testing, and a test charter must be interpretable by humans and so could be reviewed, which is a form of static testing

Explanation / Rationale

a) Is not correct. The detection of additional high-severity defects would be a benefit of test automation, rather than a risk
b) Is not correct. The provision of measures that are too complicated for humans to derive themselves is normally considered to be a benefit of test automation
c) Is correct. If the test automation is incompatible with the development platform, then it will not be able to integrate them, and, for instance, pass test inputs to the test object and receive test results from the test object
d) Is not correct. Substantially reduced test execution times would normally be considered a benefit that is provided by test automation

Explanation / Rationale

a) Is not correct. In exploratory testing, test cases are usually created during the exploratory testing session, alongside test analysis, test implementation and test execution
b) Is not correct. In exploratory testing, tests are simultaneously designed, executed, and evaluated while the tester learns about the test object
c) Is not correct. Exploratory testing results depend heavily on the tester’s experience, so even if the results of exploratory testing can be used as a predictor of risk and used to assess whether there will be fewer or more defects, for example, compared to the previous exploratory testing session, they are not a good example of reliable defect prediction models that can predict the number of remaining defects
d) Is correct. During exploratory testing, the testers can use any techniques that they find useful

Explanation / Rationale

a) Is correct. Behavior-Driven Development (BDD) is a well-known example of a test-first approach to development
b) Is not correct. Test Level Driven Development is not a correct example of a test-first approach to development
c) Is not correct. Function-Driven Development is not a correct example of a test-first approach to development
d) Is not correct. Performance-Driven Development is not a correct example of a test-first approach to development

Explanation / Rationale

a) Is correct. Each test level has specific and distinct test objectives as a different form of test object (e.g., single component, complete system) is tested at each test level and overlapping test objectives would lead to unnecessary duplication
b) Is not correct. Test analysis and design for a given test level should start during the corresponding development phase to facilitate early testing (e.g., acceptance test analysis and design should begin during requirements analysis). Test implementation will generally start later, and test execution will start during the test level
c) Is not correct. Test design for a given test level should start during the corresponding development phase to facilitate early testing, however test design (e.g., test case generation) needs to be based on an agreed test basis, not an early draft, otherwise significant test effort may be wasted on creating test cases for a design that later changes
d) Is not correct. Quality control applies to all development activities, meaning that every software development activity has a corresponding test activity. However, the same symmetry does not apply to dynamic and static testing. There are some static testing activities (e.g., static analysis) for which there is no obvious corresponding dynamic testing activity

Explanation / Rationale

a) Is not correct. Priorities for user stories are determined by the business representative together with the development team
b) Is not correct. Testers focus on both functional and non-functional aspects of the system to be tested
c) Is correct. According to the syllabus, this is one of the ways testers add value to iteration and release planning
d) Is not correct. Early test design is not part of release planning. Early test design does not automatically guarantee the release of quality software

Explanation / Rationale

a) Is not correct. In the whole-team approach, testers play a vital role by sharing their testing expertise with the team and guiding product development. They collaborate with other team members to achieve the desired quality levels and work with business representatives to create acceptance tests. Testers also partner with developers to determine the optimal test strategy and automation approaches
b) Is correct. By leveraging the diverse skill sets of each team member most effectively, the whole-team approach fosters superior team dynamics, promotes robust communication and collaboration, and generates a synergistic effect that benefits the entire project
c) Is not correct. The whole-team approach allows any team member with the requisite skills and knowledge to undertake any task, thus specialist team members are not an advantage of this approach
d) Is not correct. There is no specific guidance on the optimum size of teams using the whole-team approach, and there is no suggestion that larger teams are better

Explanation / Rationale

a) Is not correct. The rule-oriented format includes formats like bullet point verification lists or tabulated forms of input-output mappings, explicitly showing the rules to be followed. Given/When/Then is a scenario-oriented format because it describes a scenario to be verified
b) Is correct. This is a Given/When/Then format, which is scenario-oriented
c) Is not correct. There no "product-oriented" format of acceptance criteria
d) Is not correct. There is no "process-oriented" format of acceptance criteria

Explanation / Rationale

There are 12 boundary values for the final result values: 0, 50, 51, 60, 61, 70, 71, 80, 81, 90, 91, and 100.
The test cases cover six of them (TC1 – 91, TC2 – 50, TC3 – 81, TC4 – 60, TC5 – 70 and TC7 – 51).
Therefore, the test cases cover 6/12 = 50%.
Thus:
a) Is correct
b) Is not correct
c) Is not correct
d) Is not correct