Explanation / Rationale

a) Is not correct. When a user reports a software failure, thanks to the unique identification of commits, it is possible to reassemble the files from the software version which was used by the user (as well as the corresponding versions of the test scripts) and thus reproduce the failure and locate the defect faster
b) Is not correct. If a change to the test environment causes unexpected issues during testing, configuration management allows testers to roll back to a previous version of the environment. This ensures that testing can continue without being affected by the change
c) Is not correct. Configuration management ensures that all identified documentation (e.g., requirement specifications) and software items are referenced unambiguously in test documentation (e.g., test plans)
d) Is correct. This is ensured by the defect management, not configuration management process

Explanation / Rationale

a) Is not correct
b) Is not correct
c) Is not correct
d) Is correct. This rule holds for all SDLC models

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 correct. The number of defects found is related to the test object quality
b) Is not correct. This is the measure of the test efficiency not the test object quality
c) Is not correct. The number of test cases executed does not tell us anything about the quality; test results might do
d) Is correct. defect density is related to the test object quality
e) Is not correct. Time to repair is a process metric. It does not tell us anything about the product quality

Explanation / Rationale

a) Is correct. Performing only black-box testing does not provide a measure of actual code coverage. White-box coverage measures provide an objective measurement of coverage and provide the necessary information to allow additional tests to be generated to increase this coverage, and subsequently increase confidence in the code
b) Is not correct. This statement is correct, but it has nothing to do with black-box testing
c) Is not correct. In general there are no subsumes relationships between white-box and black-box techniques
d) Is not correct. White-box techniques are used to design tests based on the test object itself, while black-box techniques are used to design tests based on the specification. Therefore, there is no relation between coverage items derived from these two types of techniques

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

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

Explanation / Rationale

a) Is not correct. This is a common characteristic of white-box test techniques. Test conditions, test cases, and test data are derived from a test basis that may include code, software architecture, detailed design, or any other source of information regarding the structure of the software.
b) Is not correct. This is a common characteristic of white-box test techniques. Coverage is measured based on the items tested within a selected structure and the technique applied to the test basis
c) Is correct. This is a common characteristic of experience-based test techniques. This knowledge and experience include expected use of the software, its environment, likely defects, and the distribution of those defects is used to define tests
d) Is not correct. This is a common characteristic of black-box test techniques. Test cases may be used to detect gaps within requirements and the implementation of the requirements, as well as deviations from the requirements

Explanation / Rationale

a) Is not correct. The testing role is primarily responsible for the technical and engineering aspects of testing, such as test analysis, test design, test implementation, and test execution. Evaluating the test basis for defects and the test object for testability are tasks performed as part of test analysis, so it is likely they are tasks performed by the testing role
b) Is not correct. The testing role is primarily responsible for the technical and engineering aspects of testing, such as test analysis, test design, test implementation, and test execution. Defining the test environment requirements is a task performed as part of test design, so it is likely to be a task performed by the testing role
c) Is not correct. The testing role is primarily responsible for the technical and engineering aspects of testing, such as test analysis, test design, test implementation, and test execution. Assessing the testability of a test object is a task performed as part of test analysis, so it is likely to be a task performed by the testing role
d) Is correct. The test management role primarily involves activities related to test planning, test monitoring and control, and test completion. Thus, creating the test completion report, which is the prime output from the test completion activity, is likely to be a task performed by the test management role

Explanation / Rationale

Considering each of the listed task descriptions:

1. The quality characteristics to be evaluated and the exit criteria are selected - (Planning (C): Defining the review scope, purpose, work product to be reviewed, quality characteristics to be evaluated, areas of focus, exit criteria, supporting information such as standards, effort, and timeframes.)
2. Everyone has access to the work product - (Review initiation (B): Ensuring all participants have access to the work product and necessary resources, and clarifying their roles and responsibilities.)
3. Anomalies are identified in the work product - (Individual review (A): Evaluating the work product's quality, identifying and logging anomalies, recommendations, and questions using review techniques like checklist-based and scenario-based reviewing.)
4. Anomalies are analyzed and discussed - (Communication and analysis (D): Analyzing and discussing each anomaly, determining its status, ownership, and required actions, and making review decisions, normally in a meeting. This could include determining the need for a follow-up review.)

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

Explanation / Rationale

Branch testing is a white-box test technique in which the coverage items are branches. A branch is a transfer of control between two nodes in the control flow graph, which shows the possible sequences in which source code statements are executed in the test object. Each transfer of control can be either unconditional (i.e., straight-line code) or conditional (i.e., a decision outcome). Coverage is measured as the number of branches exercised by the test cases divided by the total number of branches, and is expressed as a percentage.
Thus:
a) Is not correct. A decision outcome is a conditional branch. For branch testing, X counts not only conditional, but also unconditional branches
b) Is not correct. Branch coverage counts not only conditional, but also unconditional branches
c) Is correct. Branch coverage is measured as the number of branches exercised by the test cases divided by the total number of branches, and is expressed as a percentage
d) Is not correct. Both X and Y count only conditional branches and do not take into account the unconditional branches

Explanation / Rationale

a) Is correct. A fundamental strength that all white-box test techniques share is that the entire software implementation is taken into account during testing, which facilitates defect detection even when the software specification is vague, outdated or incomplete. This means white-box testing can find defects such as an extra feature added to the code (either accidentally or deliberately) that is not supposed to be there, which black-box testing cannot detect
b) Is not correct. The fact that the coverage can be precisely defined is not the right reason. The achieved level of coverage would have much more impact than the possibility to measure the coverage
c) Is not correct. If the software does not implement one or more requirements, white-box testing is unlikely to detect the resulting defects of omission
d) Is not correct. While this is true, this is not the right answer, because there is no connection between the capability to be used in both static testing and dynamic testing and the claim that white-box testing facilitates defect detection with poor specifications

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. Dynamic testing does cause failures (from which defects can then be located and fixed). However, debugging is concerned with locating defects and fixing these defects. Therefore, debugging does not fix failures
b) Is not correct. Both testing and debugging contribute to improving the quality of the test object, so should really both be considered positively. Debugging is generally considered to be a positive activity as it is fixing something. Dynamic testing does involve intentionally causing the test object to fail, which is why some people consider it a negative activity, but that is a very narrow view (and not one typically held by testers). Both positive and negative test cases are possible. Positive test cases check that the test object correctly performs what it is supposed to do, while negative testing checks that the test object does not do what it is not supposed to do
c) Is correct. Testing determines that defects exist either directly through observation of the defect in reviews (or by a tool in static analysis), or indirectly by causing a failure in dynamic testing. Debugging is a separate activity from testing (normally performed by developers) and is concerned with locating defects (only for dynamic testing) and fixing the defects
d) Is not correct. The causes of defects are typically human errors. Testing finds defects either directly through static testing, or indirectly by causing failures in dynamic testing, and debugging fixes defects. So, testing does not find the cause of defects and debugging does not fix the causes of defects

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

Considering:

Testing and quality assurance are not the same. Testing is the process consisting of all software development lifecycle (SDLC) activities, both static and dynamic, concerned with planning, preparation and evaluation of a component or system and related work products to determine that they satisfy specified requirements, to demonstrate that they are fit for purpose and to detect defects. Quality assurance is focused on establishing, introducing, monitoring, improving, and adhering to the quality-related processes.

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

Explanation / Rationale

a) Is correct. Debugging is the process of finding, analyzing, and removing the causes of failures in a component or system
b) Is not correct. Testing is the process concerned with planning, preparation and evaluation of a component or system and related work products to determine that they satisfy specified requirements, to demonstrate that they are fit for purpose and to detect defects. It is not related to fixing causes of failures
c) Is not correct. Requirement elicitation is the process of gathering, capturing, and consolidating requirements from available sources. It is not related to fixing causes of failures
d) Is not correct. Defect management is the process of recognizing, recording, classifying, investigating, resolving, and disposing of defects. It is not related to fixing causes of failures

Explanation / Rationale

a) Is correct. In sequential development models, in the initial phases, testers participate in requirement reviews, test analysis, and test design. The executable code is usually created in the later phases, so dynamic testing cannot be performed early in the SDLC
b) Is not correct. Static testing can always be performed early in the SDLC
c) Is not correct. Test planning should be performed early in the SDLC before the test project begins
d) Is not correct. Acceptance testing can be performed when there is a working product. In sequential SDLC models the working product is usually delivered late in the SDLC

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

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

The following three transitions:

“REQUESTING -> CONFIRMED”
“WAITING LIST -> CONFIRMED”
“WAITING LIST -> END”

cannot appear in the same test case, which suggests that at least three test cases are required. All the other transitions can appear in combination with one or more of these three transitions, so we need a minimum of three test cases. In fact, only three sequences are possible:

TC1: START (Room request) → REQUESTING (Available) → CONFIRMED (Pay) → END
TC2: START (Room request) → REQUESTING (Not available) → WAITING LIST (Available) → CONFIRMED (Pay) → END
TC3: START (Room request) → REQUESTING (Not available) → WAITING LIST (Cancel) → END

Thus:
a) Is correct
b) Is not correct
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

According to the dependencies, SEARCH tests must be executed first, then VIEW tests, then ADD tests and, at the end, ORDER tests. Within each of these groups the order is determined by the priorities of the test cases.
So, TC1 must be executed first, then TC2, then TC4 followed by TC3, and then TC5 as the last one.
So, the ordering is: TC1, TC2, TC4, TC3, TC5.
Thus:
a) Is correct. TC3 will be the fourth test case executed
b) Is not correct
c) Is not correct
d) Is not 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

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

Because TC1 and TC3 failed in Execution 1 (i.e., test (1) and test (3)), test (4) and test (6) are confirmation tests.
Because TC2 and TC3 failed in Execution 2 (i.e., tests (5) and (6)), test (8) and test (9) are also confirmation tests.
TC2 passed in Execution 1 (i.e., test (2)), so test (5) is a regression test.
TC1 passed in the Execution 2 (i.e., test (4)), so test (7) is also a regression test.
Thus:
a) Is not correct
b) Is correct
c) Is not correct
d) Is not correct

Explanation / Rationale

a) Is not correct. Although it is correct to say that in Agile software development, some of the test management tasks may be handled by the Agile team itself, the testing role is not primarily the responsibility of a single individual from outside the team. Instead the testing is more likely to be performed by various team members following the whole-team approach
b) Is not correct. The test management role primarily involves activities related to test planning, test monitoring and control, and test completion. So, although this statement is partially correct, it is wrong to say that the testing role is primarily responsible for test monitoring and control
c) Is correct. In Agile software development, some of the test management tasks may be handled by the Agile team itself. However, for test activities that span multiple teams within an organization, test managers outside of the development team may perform these tasks
d) Is not correct. The test management role primarily involves activities related to test planning, test monitoring and control, and test completion, while the testing role is primarily responsible for the technical and engineering aspects of testing, such as test analysis, test design, test implementation, and test execution. Thus the test management role is not normally responsible for test analysis and test design, although it is correct to say that the testing role is primarily responsible for test implementation and execution

Explanation / Rationale

We want to run test cases according to their priorities, but we also need to consider the dependencies.
If we only consider priorities, we want to first run TC 5 and TC 7 (highest priority), then TC 1, TC 3, and TC 4, and finally TC 2 and TC 6 (lowest priority).
However, in order to run TC 7, we need to first run TC 4.
In order to run TC 5, we need to run TC 4 and TC 2, but TC 2 is blocked by TC 1, which should be run prior to TC 2.
So, in order to run priority 1 test cases as early as possible, the first five test cases should be: TC 4 - TC 7 - TC 1 - TC 2 - TC 5.
Next, we need to run TC 3, because it has higher priority than TC 6.
Thus the full schedule will be TC 4 – TC 7 – TC 1 – TC 2 – TC 5 – TC 3 – TC 6.
So, the sixth test case will be TC 3.

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

Explanation / Rationale

a) Is correct. When a system is retired, this can require testing of data migration, which is a form of maintenance testing
b) Is not correct. Regression testing verifies whether a fix accidentally affected the behavior of other parts of the code, but now we are talking about data migration to a new system
c) Is not correct. Component testing focuses on individual hardware or software components, not on data migration
d) Is not correct. Integration testing focuses on interactions between components and/or systems, not on data migration

Explanation / Rationale

i. Is true. The SDLC has an influence on the test process
ii. Is false. The number of defects detected in previous projects may have some influence, but this is not as significant as i, iii and iv
iii. Is true. The identified product risks are one of the most important factors influencing the test process
iv. Is true. Regulatory requirements are important factors influencing the test process
v. Is false. The test environment has no significant influence on the test process

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

Explanation / Rationale

a) Is correct. For a complex configuration item (e.g., a test environment), CM records the items it consists of, their relationships, and versions
b) Is not correct. CM tools do not execute test cases and do not calculate coverage
c) Is not correct. A CM tool is not a license management tool
d) Is not correct. CM tools do not generate test data

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

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. The test case is related to viewing previous orders in the order history
b) Is not correct. The test case is related to viewing previous orders
c) Is not correct. The test case is related to viewing previous orders in the order history
d) Is correct. The test case is related to the registration process, which is not discussed in the user story. The user story is about viewing previous orders

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

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

a) Is not correct. In agile software development, deliverables are produced in each iteration, and the frequent delivery of increments necessitates extensive regression testing. Although some (or all) of this regression testing may be automated, the regression testing (automated or not) cannot be replaced by system test automation
b) Is correct. If a sequential development model is used, then early in the lifecycle no code is available for execution, and so during this time static testing (e.g., reviews) is performed. Later in the lifecycle, when code is available for execution, dynamic testing is possible. Note, however, that preparation for dynamic testing will often occur early in any software development lifecycle
c) Is not correct. If an iterative development model, like agile software development, is used, then component tests may well be used for regression testing for each iteration. In which case, there is a strong argument for automating these component tests, which will have to be run frequently, and there is unlikely to be a strong argument for developers performing these component tests manually
d) Is not correct. In most incremental development models, deliverables are produced in each increment, requiring both static and dynamic testing at all test levels for each increment delivered

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

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. 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