WGU D421 – Software Engineering Final
Prep Exam (Latest Update 2026/2027)
Questions and Verified Answers | 100%
Correct | Grade A.
1. Which software development model emphasizes iterative
development, customer collaboration, and responding to changing
requirements?
A. Waterfall model
B. Agile model
C. V-model
D. Big Bang model
Rationale: The Agile model focuses on incremental development,
frequent feedback, collaboration with stakeholders, and adapting to
changing requirements throughout the software development lifecycle.
Waterfall is sequential, while V-model emphasizes verification and
validation.
2. What is the primary purpose of software requirements
engineering?
A. Writing source code for the application
B. Designing database tables
,C. Identifying, documenting, and managing system requirements
D. Deploying software to production
Rationale: Requirements engineering involves gathering, analyzing,
documenting, validating, and managing stakeholder needs to ensure
the software solution meets business and technical objectives.
3. Which document describes the functional and nonfunctional
requirements of a software system?
A. Test plan
B. Project charter
C. Software Requirements Specification (SRS)
D. User manual
Rationale: The Software Requirements Specification (SRS) defines what
the software must do and includes functional requirements,
performance requirements, constraints, and other system expectations.
4. In object-oriented programming, what concept allows a class to
inherit properties and behaviors from another class?
A. Encapsulation
B. Polymorphism
C. Abstraction
D. Inheritance
Rationale: Inheritance allows a child class to reuse and extend attributes
and methods from a parent class, improving code reuse and
maintainability.
, 5. Which software design principle states that a module should have
only one reason to change?
A. Open/Closed Principle
B. Dependency Inversion Principle
C. Single Responsibility Principle
D. Interface Segregation Principle
Rationale: The Single Responsibility Principle (SRP) promotes highly
focused modules by ensuring each component has one specific
responsibility, making maintenance easier.
6. What is the main purpose of version control systems such as Git?
A. Automatically generate software requirements
B. Replace software testing procedures
C. Track changes to source code and support collaboration
D. Convert source code into machine code
Rationale: Version control systems maintain a history of changes, allow
developers to collaborate, and provide mechanisms for branching,
merging, and restoring previous versions.
7. Which software testing level focuses on testing individual
components or functions?
A. Integration testing
B. System testing
, C. Acceptance testing
D. Unit testing
Rationale: Unit testing evaluates individual pieces of code, such as
functions, methods, or classes, to verify they work correctly in isolation.
8. What is the primary goal of continuous integration (CI)?
A. Eliminating the need for developers
B. Preventing all software defects
C. Automatically integrating and testing code changes frequently
D. Replacing project management processes
Rationale: Continuous integration encourages developers to frequently
merge code changes into a shared repository where automated builds
and tests identify problems early.
9. Which UML diagram is commonly used to represent interactions
between objects over time?
A. Class diagram
B. Component diagram
C. Deployment diagram
D. Sequence diagram
Rationale: Sequence diagrams show how objects communicate through
messages in a chronological sequence, making them useful for modeling
system behavior.
Prep Exam (Latest Update 2026/2027)
Questions and Verified Answers | 100%
Correct | Grade A.
1. Which software development model emphasizes iterative
development, customer collaboration, and responding to changing
requirements?
A. Waterfall model
B. Agile model
C. V-model
D. Big Bang model
Rationale: The Agile model focuses on incremental development,
frequent feedback, collaboration with stakeholders, and adapting to
changing requirements throughout the software development lifecycle.
Waterfall is sequential, while V-model emphasizes verification and
validation.
2. What is the primary purpose of software requirements
engineering?
A. Writing source code for the application
B. Designing database tables
,C. Identifying, documenting, and managing system requirements
D. Deploying software to production
Rationale: Requirements engineering involves gathering, analyzing,
documenting, validating, and managing stakeholder needs to ensure
the software solution meets business and technical objectives.
3. Which document describes the functional and nonfunctional
requirements of a software system?
A. Test plan
B. Project charter
C. Software Requirements Specification (SRS)
D. User manual
Rationale: The Software Requirements Specification (SRS) defines what
the software must do and includes functional requirements,
performance requirements, constraints, and other system expectations.
4. In object-oriented programming, what concept allows a class to
inherit properties and behaviors from another class?
A. Encapsulation
B. Polymorphism
C. Abstraction
D. Inheritance
Rationale: Inheritance allows a child class to reuse and extend attributes
and methods from a parent class, improving code reuse and
maintainability.
, 5. Which software design principle states that a module should have
only one reason to change?
A. Open/Closed Principle
B. Dependency Inversion Principle
C. Single Responsibility Principle
D. Interface Segregation Principle
Rationale: The Single Responsibility Principle (SRP) promotes highly
focused modules by ensuring each component has one specific
responsibility, making maintenance easier.
6. What is the main purpose of version control systems such as Git?
A. Automatically generate software requirements
B. Replace software testing procedures
C. Track changes to source code and support collaboration
D. Convert source code into machine code
Rationale: Version control systems maintain a history of changes, allow
developers to collaborate, and provide mechanisms for branching,
merging, and restoring previous versions.
7. Which software testing level focuses on testing individual
components or functions?
A. Integration testing
B. System testing
, C. Acceptance testing
D. Unit testing
Rationale: Unit testing evaluates individual pieces of code, such as
functions, methods, or classes, to verify they work correctly in isolation.
8. What is the primary goal of continuous integration (CI)?
A. Eliminating the need for developers
B. Preventing all software defects
C. Automatically integrating and testing code changes frequently
D. Replacing project management processes
Rationale: Continuous integration encourages developers to frequently
merge code changes into a shared repository where automated builds
and tests identify problems early.
9. Which UML diagram is commonly used to represent interactions
between objects over time?
A. Class diagram
B. Component diagram
C. Deployment diagram
D. Sequence diagram
Rationale: Sequence diagrams show how objects communicate through
messages in a chronological sequence, making them useful for modeling
system behavior.
