Explanation / Rationale

a) Is not correct. DevOps generally increases the visibility of non-functional quality characteristics, such as performance and reliability
b) Is not correct. Automated processes like continuous integration/continuous delivery (CI/CD) used in DevOps facilitate stable test environments
c) Is not correct. Automated processes like CI/CD used in DevOps generally reduce the need for manual testing
d) Is correct. DevOps implementation can pose several risks and challenges, including the need to define and set up the delivery pipeline, introduce and maintain CI/CD tools, and establish and maintain test automation

Explanation / Rationale

a) Is not correct. DevOps enhances testing in several ways, such as by providing fast feedback on code quality, automated regression testing that minimizes regression risk, and promoting a shift-left approach with high-quality code submission and component tests. This is largely provided through continuous integration, where the developers submit component (unit) tests with their new code, which must pass for the code to be admitted to the build. Therefore, developers do need to complete component testin
b) Is correct. DevOps enhances testing in several ways, such as by providing fast feedback on code quality, automated regression testing that minimizes regression risk, and promoting a shift-left approach with high-quality code submission and component tests
c) Is not correct. DevOps enhances testing in several ways, such as by providing fast feedback on code quality, automated regression testing that minimizes regression risk, and promoting a shift-left approach with high-quality code submission and component tests. Testers do not attempt to treat developers and operations equally by spending more time on release testing, although a shift-right approach to testing (testing in production) may well be used
d) Is not correct. Automated processes like continuous integration/continuous delivery (CI/CD) in DevOps facilitate stable test environments and reduce the need for manual testing, however, there is a risk of overlooking the importance of manual testing, especially from a user's perspective

Explanation / Rationale

Consider:

i. It is a Project risk
ii. It is a Product risk
iii. It is a Product risk
iv. It is a Project risk
v. It is a Product risk

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

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

a) Is not correct. This is the task of the review leader
b) Is correct. This is the task of the management in a formal review
c) Is not correct. This is the task of the moderator
d) Is not correct. This is the task of the scribe

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

Explanation / Rationale

The equivalence partitions are: {…, 99, 100}, {101, 102, …, 198, 199}, {200, 201, …}.
Thus, there are 4 boundary values, which are: 100, 101, 199 and 200.
In 2-value BVA, for each boundary value there are two coverage items (the boundary value and its closest neighbor belonging to the adjacent partition). As the closest neighbors are also boundary values in the adjacent partition, then there are just four coverage items.

Thus:
a) Is not correct. Only 100 and 200 are valid coverage items for 2-value BVA, so we achieve 50% coverage
b) Is not correct. Only 100 and 200 are valid coverage items for 2-value BVA, so we achieve 50% coverage
c) Is not correct. Only 100 and 101 are valid coverage items for 2-value BVA, so we achieve 50% coverage
d) Is correct. 101, 199 and 200 are valid coverage items for 2-value BVA, so we achieve 75% coverage

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

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

Consider:

i. These behaviors are easily detectable while the software is running. Hence, dynamic testing shall be used to identify them
ii. This is an example of deviations from standards, which is a typical defect that is easier found with static testing
iii. If the software is executed during the test, it is dynamic testing
iv. Identifying defects as early as possible is the test objective of both static testing and dynamic testing
v. This is an example of gaps in the test basis traceability or coverage, which is a typical defect that is easier found with static testing

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

Explanation / Rationale

a) Is not correct. Quality should be the responsibility of everyone working on the project and not the sole responsibility of the test team
b) Is not correct. First, it is not a benefit if an external test team does not meet delivery deadlines, and second, there is no reason to believe that external test teams will feel they do not have to meet strict delivery deadlines
c) Is not correct. It is bad practice for the test team to work in complete isolation, and we would expect an external test team to be concerned with changing project requirements and communicating well with developers
d) Is correct. Specifications are never perfect, meaning that assumptions will have to be made by the developer. An independent tester is useful in that they can challenge and verify the assumptions and subsequent interpretation made by the developer

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

a) Is correct. This test covers two acceptance criteria: one about editing the document and one about saving changes
b) Is not correct. Acceptance criteria cover the editor activities, not the content owner activities
c) Is not correct. Scheduling the edited content for publication may be a nice feature, but it is not covered by the acceptance criteria
d) Is not correct. Acceptance criteria state about reassigning from an editor to the content owner, not to another editor

Explanation / Rationale

a) Is not correct. The document does not refer to the test object’s internal structure but specifies the desired behavior of the test object. Therefore, white-box test techniques will not be helpful in designing test cases
b) Is correct. The document is a requirement that specifies the desired behavior of the test object. Therefore, the most suitable test techniques in this case are the black-box test techniques (e.g., Boundary Value Analysis or Decision Table Testing)
c) Is not correct. Although experience-based test techniques can be used to design test cases based on this document, black-box test techniques will be more suitable. The document describes a precise business rule and, in addition, wording like "exceeds $100" suggests the existence of important equivalence partition boundaries that should be tested using black-box test techniques like boundary value analysis
d) Is not correct. Risk-based test techniques are not a recognized type of test technique

Explanation / Rationale

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

Explanation / Rationale

a) Is not correct. 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

Risk assessment can use a quantitative or qualitative approach, or a mix of them. In the quantitative approach the risk level is calculated as the multiplication of risk likelihood and risk impact. So, Risk level = Risk likelihood * Risk impact
Then, Risk impact = Risk level / Risk likelihood.
In our case, Risk impact = $1,000 / 50% = $1,000 / 0.5 = $2,000.
Thus:
a) Is not correct
b) Is correct
c) Is not correct
d) Is not correct

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

The domain for the password length has three equivalence partitions:

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

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

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

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

0, 5, 6, 12 and 13.

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

1, 4, 7, 11 and 14.

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

Explanation / Rationale

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. 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. Decision table testing is a black-box test technique, so it is specification-based, not structure-based – the test cases are not based on the decisions in the source code. In branch testing, the test cases are derived from knowledge of the control flow of the test object
b) Is not correct. Anticipation of potential defects is used in error guessing (an experience-based test technique), not in branch testing (a structure-based technique). In decision table testing, the test cases are derived from the specification that describes the business logic
c) Is not correct. If a test case is based on the knowledge of the control flow of the test object, it is a white-box test technique. Decision table testing is typically based on an analysis of business logic, so it is a black-box test technique. In branch testing, test cases are not derived from the specification – this would make it a black-box test technique. Branch testing is a white-box test technique, where test cases are derived based on the source code structure
d) Is correct. Decision table testing is a black-box test technique, so it is based on an analysis of the specified behavior of the test object without reference to its internal structure. Therefore, the test cases are independent of how the software is implemented. Branch testing is a white-box test technique, so test cases are based on an analysis of the test object’s internal structure and processing. As the test cases are dependent on how the software is designed and coded, they can only be created after the design or implementation of the test object

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

Explanation / Rationale

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

Explanation / Rationale
a) Is not correct. Retrospectives are used to capture lessons learned and to improve the development and testing process, not to document the acceptance criteria
b) Is correct. This is the standard way to document acceptance criteria
c) Is not correct. Verbal communication does not allow to physically document the acceptance criteria as part of a user story (”card” aspect in the 3C’s model)
d) Is not correct. Acceptance criteria are related to a user story, not a test plan. Also, acceptance criteria are the conditions that have to be fulfilled to decide if the user story is complete. Risks are not such conditions

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

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

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

Explanation / Rationale

a) Is not correct. Traceability between the mitigated risks and passing test cases provides little information, because to be mitigated (by testing) the risks would need to have a corresponding passing test case. To be able to assess residual risk, traceability between all risks and test results needs to be available, so that the risks that do not have a corresponding passing test can be identified as the residual risks
b) Is correct. Traceability between user requirements and test execution results provides an indication of which user requirements have been tested and so provides a means of measuring project progress (in the context of testing) against business goals
c) Is not correct. It is not clear that failing test cases provide an indication of tester skills any more than passing test cases. It would partly depend on the test objective (e.g., building confidence or causing failures). Also, such measurement of testers based on passing and failing test cases can be counter-productive as it could cause the testers to optimize their testing based on that metric rather than the test objective
d) Is not correct. Traceability between the identified risks and written test conditions provides a means of determining which further test conditions need to be written. Determining which risks are worth testing is part of risk management, and risk mitigation in particular

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

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

a) Is not correct. Scope creep is an example of a project risk related to technical issues
b) Is correct. Poor architecture is an example of a product risk since it refers to a product characteristic
c) Is not correct. Cost-cutting is an example of a project risk, related to organizational issues
d) Is not correct. Poor tool support is an example of a project risk related to technical issues
e) Is correct. Response time too long is an example of a product risk since it refers to a product characteristic

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

Explanation / Rationale

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