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. The whole-team approach allows any team member with the requisite skills and knowledge to undertake any task, however that does not mean that team members can take on any role at any time. Typically, they only take on roles in which they are competent, and there is no suggestion that every team member can do every role
b) Is not correct. The whole-team approach applies to how a single team (typically in Agile software development) works; it does not cover how multiple teams are supposed to work on larger projects, and it does not suggest that only one ‘whole’ team is needed for a complete project
c) Is not correct. The whole-team approach does not expect every team member to be involved in every important decision. For instance, there is no need for the business representative (i.e. the Product Owner) to be involved in every technical decision that does not affect the business outcome and implementing such an approach would unnecessarily slow down the team’s progress
d) 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 team synergy that benefits the entire project

Explanation / Rationale

a) Is not correct. Test environment readiness is a resource availability criterion; hence it belongs to the entry criteria
b) Is not correct. This is a resource availability criterion; hence it belongs to the entry criteria
c) Is correct. Estimated defect density is a measure of diligence; hence it belongs to the exit criteria.
d) Is not correct. Requirements translated into a given format result in testable requirements; hence it belongs to the entry criteria
e) Is correct. Automation of regression tests is a completion criterion; hence it belongs to the exit criteria

Explanation / Rationale

a) Is correct. Defect management is no less expensive. Finding and fixing defects later in SDLC is more costly
b) Is not correct. This is a benefit of static testing
c) Is not correct. This is a benefit of static testing
d) Is not correct. This is a benefit of static testing

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

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 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 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

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. 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

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

a) Is correct. System testing examines the behavior and capabilities of the complete system and covers non-functional testing of quality characteristics, which includes security testing. This type of testing is often performed by an independent test team based on system specifications
b) Is not correct. System integration testing examines the interfaces with other systems and external services
c) Is not correct. Beta testing is a type of acceptance testing performed at an external site by roles outside the development organization
d) Is not correct. Component integration testing involves testing the (interfaces and) interactions between components of a system, such as the user interface and database

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. Testing quadrants group test levels and test types separately according to several criteria. They do not represent any combinations of test levels and test types and they are not related to any location within a software development lifecycle. Both test levels and test types are treated separately in the testing quadrants model
b) Is not correct. Testing quadrants group test levels and test types according to several criteria. They do not describe the degree of granularity of individual test types performed at each test level. Such a model, regarding the test levels, is called the test pyramid
c) Is not correct. The statement is wrong, because in general any test type can be performed at any test level
d) Is correct. The testing quadrants group test levels, test types, activities, test techniques and work products in Agile software development. In this model, tests can be business facing or technology facing. Tests can support the team (i.e., guide the development) or critique the product (i.e., measure its behavior against expectations). The combination of these two viewpoints determines the four quadrants

Explanation / Rationale

Given the following description of 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. The systematic identification of test conditions as coverage items often involves using test techniques both during test analysis and as part of the test design activity.
From the above description, it can be seen that test techniques are often used in the test analysis and test design activities. Boundary value analysis and equivalence partitioning are test techniques.
a) Is not correct. Test implementation is not likely to involve the use of test techniques as it is mostly concerned with assembling test cases into test procedures, while test techniques create test cases
b) Is correct. Test design is likely to involve the use of test techniques to create test cases from test conditions and coverage items
c) Is not correct. Test execution is not likely to involve the use of test techniques as it is mostly concerned with executing test procedures (and so test cases), while test techniques create test cases
d) Is not correct. Test monitoring is not likely to involve the use of test techniques. Test monitoring is mostly concerned with ongoing checks to ensure the plan is being followed, while test techniques create test cases
e) Is correct. Test analysis is likely to involve the use of test techniques to identify test conditions

Explanation / Rationale

a) Is not correct. A line with a defect, when executed, does not have to cause a failure. For example, a line x := y / z will cause a failure only when z equals 0
b) Is not correct. 100% statement coverage does not guarantee 100% branch coverage. For example, a test case with x=0 for the code

1. IF (x=0) THEN
2. A;
3. ENDIF

achieves 100% statement coverage but does not cover the branch from 1 to 3
c) Is correct. 100% statement coverage means that each executable statement was executed at least once
d) Is not correct. The removed test case may provide coverage of some statements that are not covered by either of the other two test cases, in which case the remaining two test cases together will not achieve 100% statement coverage

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. 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. 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. 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. This should be a team activity and not overruled by one team member
b) Is correct. If test estimates are not the same, but the variation in the results is small, applying rules like “accept the number with the most votes” can be applied
c) Is not correct. There is no consensus yet as some say 13, others say 8
d) Is not correct. A feature should not be removed only because the team cannot agree on the test estimates

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. Traceability is the relationship between two or more work products, not between different versions of the same work product
b) Is not correct. Maintenance testing is about testing changes; it is not related closely to versioning
c) Is correct. To support testing, configuration management may involve the version control of all test items
d) Is not correct. Requirements engineering is the elicitation, documentation, and management of requirements; it is not closely related to test script versioning

Explanation / Rationale

a) Is correct. 19 covers the “no discount” partition, 20 covers the “50% discount” partition, and 30 covers the “10% discount” partition. These three values cover all three of the valid equivalence partitions
b) Is not correct. 11 and 12 cover the “no discount” partition, while 20 covers the “50% discount” partition, so covering two of the three valid equivalence partitions
c) Is not correct. 1 covers the “no discount” partition, while 10 and 50 cover the “10% discount” partition. The “50% discount” partition is not covered, so overall two of the three valid equivalence partitions are covered
d) Is not correct. 29 and 31 cover the “no discount” partition, while 10 and 30 cover the “10% discount” partition. The “50% discount” partition is not covered, so overall two of the three valid equivalence partitions are covered

Explanation / Rationale

“Small garden” and “large garden” can go only with “ground floor”, so we need two test cases with “ground floor” which cover these two “garden type” partitions.
We need two more test cases to cover the two other “floor” partitions and a remaining ”garden type” partition of “no garden”.
We need a total of four test cases:

TC1 (ground floor, small garden)
TC2 (ground floor, large garden)
TC3 (first floor, no garden)
TC4 (second or higher floor, no garden)

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

Explanation / Rationale

a) Is correct. Value “1” covers “length incorrect” and covers “number of different digits incorrect”, however the system would not validate against this partition when hitting the first incorrect partition. Value “1111” covers “length correct” and “number of different digits incorrect. Value “1234” again covers “length correct” and also “number of different digits correct”
b) Is not correct. These three values achieve full coverage of the equivalence partitions, but full coverage can be achieved with two values
c) Is not correct. These two values only cover “number of different digits
d) Is not correct. These two values does not cover “number of different digits incorrect” equivalence partition

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 testware, and the test activity that produces it:

i. The test completion report is an output of the test completion activity
ii. Data held in a database used for test inputs and expected results is the test data - output of test implementation activity
iii. The list of elements needed to build the test environment is the test environment requirements - output of test design activity.
iv. Documented sequences of test cases in execution order are the test procedures - output of test implementation activity
v. Test cases - output of test design activity

Test implementation produces the following outputs: test procedures (iv), automated test scripts, test suites, test data (ii), test execution schedule, and test environment elements such as stubs, drivers, simulators, and service virtualizations.

Thus:
a) Is correct. Items ii and iv in the list are produced as a result of test implementation
b) Is not correct
c) Is not correct
d) Is not correct

Explanation / Rationale

a) Is not correct. Planning poker can estimate effort for a user story that is already written. It does not help in understanding what should be delivered
b) Is not correct. Reviews are not a collaborative user story writing practice
c) Is not correct. Iteration planning is a project-related practice, used to plan the work, not to understand what needs to be delivered
d) Is correct. Conversation explains how the software will be used and often allows the team to define meaningful acceptance criteria, thus obtaining a shared vision of what should be delivered

Explanation / Rationale

a) Is correct. The basic concept behind error guessing is that the tester tries to guess what errors may have been made by the developer and what defects may be in the test object based on past experience (and sometimes checklists)
b) Is not correct. Although a testers who used to be a developer may use their personal experience to help them when performing error guessing, the test technique is not based on prior knowledge of development
c) Is not correct. Error guessing is not a usability technique for guessing how users may fail to interact with the test object
d) Is not correct. Duplicating the development task has several flaws that make it impractical, such as the tester having equivalent skills to the developer and the time involved to perform the development. It is not error guessing

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

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. 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

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 correct. The client is in a different location and time zone, so it may be difficult to communicate face-to-face
b) Is not correct. Dashboards are usually available to any user at any time, so the difference in time zones will not be as much of a hindrance to communication as verbal, face-to-face communication
c) Is not correct. Although the time difference between Europe and America is several hours, and this may cause some inconvenience, it's certainly not as great as with communicating face-to-face
d) Is not correct. Video conferencing tools are a convenient means of communication. Although communication between Europe and America during working hours usually requires one party to connect in the very early or very late hours, this is not as much of an inconvenience as verbal, face-to-face communication

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 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

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. 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

a) Is not correct. Feedback can improve the test process, but if one only wants to improve future projects, the feedback does not need to come early or frequently
b) Is not correct. Feedback is not used to prioritize requirements
c) Is not correct. The quality of changes can be measured in multiple ways
d) Is correct. Early and frequent feedback allows for the early communication of potential quality problems