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

In branch testing the coverage items are branches, which are represented by the edges of a control flow graph. There are 8 edges in the control flow graph.
Thus:
a) Is not correct
b) Is not correct
c) Is correct
d) Is not correct

Explanation / Rationale

a) Is not correct. While the sentence is true, it does not provide much value for the developer
b) Is correct. From the test results it seems that the system ignores duplicates and sorts the list disregarding the repetitions. This is probably the cause of failures in TC3, TC4, TC5. Such information may help the developer to find the defect and fix it more efficiently
c) Is not correct. The system does not fail in sorting negative numbers. The problem is rather in disregarding duplicates
d) Is not correct. The test cases TC3, TC4 and TC5 fail, but we aren’t aware that the test cases have any defects

Explanation / Rationale

a) Is not correct. Checklists should contain test conditions to be verified. This is an example of an error, not a test condition; even if the tester was able to deduce some potential test conditions from the examples of errors, this error description is too general
b) Is not correct. Checklists should not contain items that are better suited as exit criteria. This is an example of an exit criterion
c) Is not correct. Checklists should not contain items that are too general. This is a very general item, which practically describes the goal of testing
d) Is correct. This is an example of a test condition that can be checked by a human

Explanation / Rationale

a) Is not correct. Confirmation testing to check that the updates have resulted in a correct implementation is necessary, however, it would then be sensible to perform regression testing to ensure that no defects have been introduced or uncovered in unchanged areas of the system
b) Is correct. Confirmation testing will check that the updates have resulted in a correct implementation, and then regression testing will be used to ensure that no defects have been introduced or uncovered in unchanged areas of the system
c) Is not correct. Regression testing should be used to ensure that no defects have been introduced or uncovered in unchanged areas of the system when the update was made, however it is also necessary to perform confirmation testing that will check that the updates have resulted in a correct implementation
d) Is not correct. Confirmation testing will check that the updates have resulted in a correct implementation, and regression testing will be used to ensure that no defects have been introduced or uncovered in unchanged areas of the system. However, when performed (i.e., when an update needs to be tested), confirmation testing precedes regression testing

Explanation / Rationale

a) Is not correct. The fact that the requirement about the system’s performance comes directly from the client and that the performance is important from the business point of view (i.e., high priority) does not make these tests functional, because they do not check “what” the system does, but “how” (i.e., how fast the orders are processed)
b) Is correct. This is an example of performance testing, a type of non-functional testing
c) Is not correct. From the scenario we do not know if interacting with the user interface is a part of the test conditions. But even if we did, the main test objective of these tests is to check the performance, not the usability
d) Is not correct. We do not need to know the internal structure of the code to perform the performance testing. One can execute performance efficiency tests without structural knowledge

Explanation / Rationale

In the three-point estimation technique:

E = (optimistic + 4*most likely + pessimistic)/6

E = (2+(4*11)+14)/6 = 10

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

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

a) Is correct. Test automation can provide measures that are too complicated for humans to derive, such as white-box test coverage measures for all but the most trivial code
b) Is not correct. By using test tools the responsibility for the testing is NOT shared with the tool vendor as the vendor is not involved in the testing, and it is the tester’s responsibility. The only possible responsibility that could be assigned to the tool vendor is if the tool fails to work as expected and provides incorrect test results
c) Is not correct. Testers still need to perform critical thinking when analyzing anomalies in the test results to determine their likely cause
d) Is not correct. Neither testers nor tools can generate test cases simply from an analysis of the program code as the code is the implementation and provides no information on the expected results, which will need to come from another part of the test basis, such as the design specification

Explanation / Rationale

There are two equivalence partitions that are not yet covered, which correspond to “student discount” and “pensioner discount”.
a) Is not correct. CY – BY = 64, so these inputs correspond to the already covered “no discount” partition
b) Is correct. CY – BY = 65, so these inputs correspond to a partition that is not yet covered (“pensioner discount”)
c) Is not correct. CY – BY = –65, so these inputs correspond to the already covered “error message” partition
d) Is not correct. CY – BY = 18, so these inputs correspond to the already covered “no discount” partition
e) Is correct. CY – BY = 0, so these inputs correspond to a partition that is not yet covered (“student discount”)

Explanation / Rationale

a) Is not correct. The test pyramid model does not provide information about test priorities
b) Is correct. The test pyramid model shows that different tests have different levels of granularity
c) Is not correct. The test pyramid model is independent of coverage criteria
d) Is not correct. Test pyramid model does not show any relations between different tests

Explanation / Rationale

Let us refer to the transitions with E1, …, E5 as in the picture. The variable N denotes the number of elements currently stored. Each “Add” event increases it by 1, and each “Remove” event decreases it by 1. Notice, that when the “Add” event occurs while being in the NOT FULL state, the state changes to FULL only if N=2. If N<2, the system stays in the NOT FULL state. If N=0, no “Remove” action is possible. Similarly, if N=3, no “Add” action is possible.

Test a) can be written as E1, E3, E3, E2, E4 (so covers 4 out of 5 valid transitions, achieving 80% valid transitions coverage).
Test b) is infeasible, because after the first three “Add” actions the system is in the FULL state and there is no valid transition going from FULL triggered by the “Add” event. After the first three transitions only 60% of valid transitions coverage is achieved.
Test c) can be written as E1, E2, E4, E5, E3 (so covers 5 out of 5 valid transitions, achieving 100% valid transitions coverage).
Test d) can be written as E1, E2, E4, E5, E4 (so covers 4 out of 5 valid transitions, achieving 80% valid transitions coverage).

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

Explanation / Rationale

a) Is not correct. Adequate time for individuals is a success factor
b) Is not correct. Splitting work products into small adequate parts is a success factor
c) Is not correct. Avoiding behaviors that might indicate boredom, exasperation, etc. is a success factor
d) Is correct. During reviews one can find defects, not failures

Explanation / Rationale

From the graph we have:

A(4)=6 and A(3)=8 (the last two gray boxes).

From the formula we obtain:

E(5) = (3*A(4) + A(3)) / 4 = (3*6+8) / 4 = 26 / 4 = 6.5 person-days.

Thus:
a) Is not correct
b) Is not correct
c) Is 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. Practices involved in shift-left testing are aimed at implementing more testing activities in the early phases of the development life cycle, portraying the SDLC as moving from left to right. There is no such thing as the left-hand side of the test process
b) Is correct. Shift-left emphasizes the importance of starting testing earlier in the software development lifecycle (SDLC). Implementing shift-left testing necessitates additional training, and increased effort and costs during the early stages of the SDLC, nevertheless, overall savings should be higher
c) Is not correct. Although automated component tests and component integration tests for regression testing are generally valuable, the creation of these tests is normally the responsibility of the developers, and if a continuous integration/continuous delivery (CI/CD) approach is followed, then these tests will have been submitted with the code. In some situations the tester may automate tests for regression testing, and sometimes even for component tests and component integration tests, however this is not part of a ‘shift-left’ approach which moves testing earlier in the SDLC
d) Is not correct. Training testers to perform tasks early in the SDLC would support a shift-left approach by emphasizing the importance of starting testing earlier in the SDLC. However, automating more test activities to be performed later in the SDLC is not part of a ‘shift-left’ approach

Explanation / Rationale

a) Is correct. The ‘tests wear out’ principle is concerned with the idea that repeating identical tests on unaltered code is unlikely to uncover novel defects and therefore, modifying tests may be essential. By using high-level test conditions to generate new tests each time, the tests will not be identical and should not ‘wear out’
b) Is not correct. The ‘absence-of-defects fallacy’ principle is concerned with ensuring that users’ needs are fulfilled even if lots of testing is done and no defects are found (i.e., validation is also necessary). The use of high-level test conditions to generate test cases and execute tests does not directly address this concern
c) Is not correct. 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. This is typically addressed by starting testing (both static and dynamic) as early as possible, but this is not addressed by using high-level test conditions to generate test cases and execute tests
d) Is not correct. The ‘Defects cluster together’ principle is concerned with the distribution of defects in a system, which typically follows a Pareto distribution. The use of high-level test conditions to generate test cases and execute tests does not address this concern, which is typically addressed by risk-based testing

Explanation / Rationale

a) Is not correct. In all types of reviews there is more than one role, even in informal ones
b) Is correct. There are several activities during the formal review process
c) Is not correct. Documentation to be reviewed should be distributed as early as possible
d) Is not correct. Defects found during the review should be reported

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 correct. Since 100% statement coverage is achieved, every statement, including the ones with defects, must have been executed and evaluated at least once
b) Is not correct. Coverage depends on what is tested, not on the number of test cases. For example, for code “if (x==0) y=1”, one test case (x=0) achieves 100% statement coverage, but two test cases (x=1) and (x=2) together achieve only 50% statement coverage
c) Is not correct. If there is a loop in the code there may be an infinite number of possible paths, so it is not possible to execute all the possible paths in the code
d) Is not correct. Exhaustive testing is not possible (see the seven testing principles section in the syllabus). For example, for code “input x; print x” any single test with arbitrary x achieves 100% statement coverage, but covers one input value

Explanation / Rationale

a) Is not correct. Usability testing is business facing testing that critiques the product (Q3)
b) Is not correct. Functional testing is business facing testing (Q2)
c) Is not correct. User acceptance testing is business facing testing that critiques the product (Q3)
d) Is correct. Component integration testing is technology facing testing that supports the team (guides the development) (Q1)

Explanation / Rationale

There are five columns in the decision table. Each test case covers one of them.

TC1 and TC2 both cover Rule 4
TC3 and TC4 both cover Rule 2
TC5 covers Rule 5

So, these five test cases cover three out of five columns, achieving a coverage of (3/5)*100% = 60%. Therefore, option b) is the CORRECT option.
Thus:
a) Is not correct
b) Is correct
c) Is not correct
d) Is not correct

Explanation / Rationale

a) Is not correct. Coverage is always defined as the percentage of the covered elements. Therefore, it cannot exceed 100%
b) Is correct. If the statements executed by T1 and T2 were disjoint, the coverage of the test suite {T1, T2} would be 105%, which is impossible (see answer a). Therefore, at least 5% of executable statements must have been executed by both T1 and T2
c) Is not correct. Statement coverage does not tell us anything about the number of non-executable statements in the code
d) Is not correct. Even if a test suite achieves full statement coverage, this does not imply achieving full branch coverage

Explanation / Rationale

a) Is not correct. The miscalculation of bonuses is a failure by the system, not a defect
b) Is not correct. The system not suitably supporting disabled users is a failure which eventually results in a fine, but the fine itself is not a failure (it appears to be the correct functioning of the regulatory system)
c) Is correct. The error is made by the programmer and this mistake is caused by them working under severe time pressure, which is the root cause of the subsequent defect
d) Is not correct. The poor design of the user interface, which does not suitably address disabled users, is a design defect caused by the designer error. Thus the design of the user interface includes a design defect not a designer error

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. 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

Error guessing is about anticipating the errors, defects and failures based on the tester’s knowledge.
a) Is not correct. This is an example of anticipating the developer’s error
b) Is not correct. This is an example of anticipating the defect
c) Is correct. This is an example of a potential root cause of a defect, which is neither an error, defect nor failure, and difficult for the tester to anticipate
d) Is not correct. This is an example of anticipating a failure, perhaps based on experience of previous systems in this application domain

Explanation / Rationale

TC1 achieves the highest coverage (4/7 – Req1, Req3, Req4 and Req7), so should be executed first.
Req2, Req5 and Req6 are still not covered.
The next test case that achieves the highest additional coverage of the remaining requirements is TC3, covering 2 out of these 3 requirements (Req5 and Req6). So, TC3 should be executed as the second one.
Now the only requirement still not covered is Req2, which is covered by TC4. Therefore, TC4 should be executed as the third test case.
So, the last test case executed will be TC2.

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

Explanation / Rationale

a) Is correct. This is done by the testers
b) Is not correct. The product backlog is built and maintained by the product owner
c) Is not correct. This is done by the development team
d) Is not correct. This is a managerial role
e) Is correct. This is done by the testers

Explanation / Rationale

Consider:

i. Is true. Faster product release and faster time to market is an advantage of DevOps
ii. Is false. Typically, we need less effort for manual tests because of the use of test automation
iii. Is true. Constant availability of executable software is an advantage
iv. Is false. More regression tests are needed
v. Is false. Not everything is automated and setting up a test automation framework is expensive

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

Explanation / Rationale

a) Is not correct. The benefits of retrospectives include team bonding and learning from sharing issues, and better collaboration between developers and testers through reviewing and improving working practices. Calling out individuals who a team member may feel did not fully contribute to achieving quality as required by the whole-team approach will not contribute to this team bonding and collaboration
b) Is correct. During the retrospective, the group discusses what aspects of the project were successful and should be retained, as well as areas that could be improved, and how to do so
c) Is not correct. The benefits of retrospectives are based on increased effectiveness and efficiency through process improvements; they are not an opportunity to let off steam and criticize management and customers. Also, the results are recorded, usually in the test completion report, so anything said in the meeting could be read by other stakeholders
d) Is not correct. Retrospectives are meetings that are typically held at the end of an iteration where team members will focus on discussing quality-related issues that have occurred in the current iteration. They are not used for making plans or technical decisions for the next iteration; this would be done in the iteration planning meeting at the start of the next iteration

Explanation / Rationale

Considering each of the listed tool categories and their descriptions:

A. Static testing tools – support the tester in performing reviews and static analysis (4)
B. Tools supporting scalability and deployment standardization – For example, virtual machines, containerization tools (3)
C. DevOps tools – support the DevOps delivery pipeline, workflow tracking, automated build process(es), continuous integration/continuous delivery (CI/CD) (1)
D. Collaboration tools – facilitate communication (2)

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

Explanation / Rationale

Considering the attributes:

• Specified for walkthroughs, technical reviews, and inspections; thus, the reviews being performed cannot be informal reviews
• The purpose of evaluating quality is one of the most important objectives of a walkthrough
• This is not allowed for inspections and is typically not done in technical reviews. A moderator is needed in walkthroughs and is allowed for informal reviews
• All types of reviews can include individual preparation (even informal reviews)
• All types of reviews can produce a review report, although informal reviews do not require documentation

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

Explanation / Rationale

Considering each of the listed benefits and drawbacks of the independence of testing:

i. Ideally, we want close collaboration between testers and developers, which is not increased by isolation. Thus, this is a disadvantage
ii. Testers and developers have varied backgrounds, technical viewpoints, and potential biases, allowing testers to usefully challenge assumptions made by stakeholders during system specification and implementation. Thus, this is an advantage
iii. 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. Thus, this is a disadvantage
iv. One of the disadvantages of independence in testing is that testers may become isolated from the development team, leading to developers feeling less accountable for quality. Thus, this is a disadvantage
v. 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

Thus:
a) Is not correct
b) Is correct. The list entries showing benefits are ii and v
c) Is not correct
d) Is not correct

Explanation / Rationale

a) Is not correct. Test execution and coverage tools facilitate the automated execution of test cases and the measurement of the coverage achieved by running those test cases. However, these tools do not help with the organization of defects and configuration management
b) Is not correct. Test design and implementation tools facilitate the generation of test cases, test data and test procedures, but they do not help with the organization of defects and configuration management
c) Is not correct. Defect management tools are used to manage defects but are not testing tools and are not used to organize test cases or configuration management
d) Is correct. Test management tools increase the test process efficiency by facilitating the management of the software development lifecycle (SDLC), requirements, tests, defects, and configuration management

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

Exploratory testing is useful when there are few or inadequate specifications or there is significant time pressure on the testing. Exploratory testing is also useful to complement other more formal test techniques. Exploratory testing will be more effective if the tester is experienced, has domain knowledge and has a high degree of essential skills, like analytical skills, curiosity and creativeness.

Thus:
a) Is correct. Exploratory testing is useful when there are few or inadequate specifications or there is significant time pressure on the testing
b) Is not correct. Exploratory testing is not a black-box test technique
c) Is not correct. Exploratory testing is useful when the specifications are poorly written
d) Is not correct. Programming skills have nothing to do with exploratory testing in principle
e) Is correct. Exploratory testing will be more effective if the tester is experienced, has domain knowledge and has a high degree of essential skills, like analytical skills, curiosity and creativeness

Explanation / Rationale

a) Is not correct. Although it is true that the tester can implement and execute detailed test cases based on the checklist, it does not explain how this would result in increased coverage
b) Is not correct. Checklist items should not be automated. But even if they are, the automated test scripts always execute the tests in the same way, which usually does not result in increased coverage
c) Is not correct. It is true that each checklist item should be tested separately and independently. But this impacts the test execution order and does not impact the achieved coverage, and so does not result in increased coverage
d) Is correct. If the checklists are high-level, some variability in the actual testing is likely to occur, resulting in potentially greater coverage but less repeatability. If two testers follow a checklist of high-level items, each of them may use different test data, test steps, etc. This way, one tester will probably cover some areas not covered by the other tester and this will result in increased coverage

Explanation / Rationale

The ‘absence-of-defects fallacy’ is concerned with the idea that ensuring correctness in accordance with the requirements (i.e., verifying the absence of implementation defects) does not guarantee user satisfaction with the system. To address this it is also necessary to validate that the system meets users' needs and expectations, fulfills business objectives, and outperforms competing systems.
a) Is not correct. The ‘testing shows the presence, not the absence of defects’ principle explains that while testing can detect the existence of defects in the test object, it is not possible to demonstrate that there are no defects and, therefore, guarantee its correctness. Therefore, explaining that it is not possible for testing to show the absence of defects would partially address this principle, not the ‘absence-of-defects’ fallacy
b) Is correct. By supporting the end user to perform acceptance testing it should be possible to validate that the system meets users' needs and expectations
c) Is not correct. It is not possible to ensure that no implementation defects remain in the delivered system as the ‘testing shows the presence, not the absence of defects’ principle explains that while testing can detect the existence of defects in the test object, it is not possible to demonstrate that there are no defects and, therefore, guarantee its correctness
d) Is not correct. Modifying tests that cause no failures to ensure few defects remain is one way to address the ‘tests wear out’ principle. This principle is concerned with the idea that repeating identical tests on unaltered code is unlikely to uncover novel defects and therefore, modifying tests may be essential. This will not validate that the system meets users' needs and expectations

Explanation / Rationale

a) Is correct. Checking that the sort function puts the elements of the list or array in ascending order is evaluating the functional correctness of the sort function, which is part of functional testing
b) Is not correct. Assessing whether the sort function meets its non-functional requirement to complete within one second is part of testing its performance efficiency, which is part of non-functional testing
c) Is not correct. Evaluating the ease with which the sort function can be modified from sorting ascending to sorting descending is testing its modifiability, a form of non-functional maintainability testing, which is part of non-functional testing
d) Is not correct. Assessing that the sort function still functions correctly when moved from a 32-bit to a 64-bit architecture is testing its adaptability, a form of portability testing, which is part of non-functional testing