Quick Answer
The answer is unit testing. This is the correct choice because unit testing is the phase in system development where developers test individual program units or modules in isolation, verifying that each component functions correctly according to its design specifications. It is the lowest level of testing, often using stubs and drivers to simulate interfaces with other parts of the system, ensuring that each unit behaves as intended before integration. On the CISA exam, this question tests your understanding of the software development lifecycle and the distinct roles of testing phases; a common trap is confusing unit testing with integration testing, which focuses on interactions between modules rather than individual units. Remember the memory tip: “Unit = One,” meaning each single program unit is tested alone by the developer, not by the quality assurance team.
This CISA practice question tests your understanding of information systems acquisition, development and implementation. Read the scenario carefully and evaluate each option against the stated constraints before committing to an answer. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
During system development, which testing phase is performed by developers to verify that individual program units function correctly?
Integration testing
Why wrong: Integration testing checks interaction between modules.
User acceptance testing
Why wrong: UAT is performed by end users, not developers.
Unit testing
Unit testing verifies individual program units.
System testing
Why wrong: System testing tests the entire system.
Answer choices
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
Unit testing
Unit testing is the phase where developers test individual program units or modules in isolation to verify they function correctly according to their design specifications. This is the lowest level of testing and is typically performed using stubs and drivers to simulate interfaces with other components.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
For each option: why learners choose it and why it is or isn't the right answer here.
Integration testing
Why it's wrong here
Integration testing checks interaction between modules.
User acceptance testing
Why it's wrong here
UAT is performed by end users, not developers.
Unit testing
Why this is correct
Unit testing verifies individual program units.
Related concept
Read the scenario before looking for a memorised answer.
System testing
Why it's wrong here
System testing tests the entire system.
Common exam traps
The trap here is confusing the scope of testing phases: candidates often mistake integration testing (which tests module interactions) for unit testing (which tests individual modules in isolation), especially when the question emphasizes 'by developers' and 'individual program units'.
Detailed technical explanation
Unit testing often employs test harnesses and mocking frameworks (e.g., JUnit, NUnit, pytest) to isolate the unit from dependencies. Developers write test cases that cover boundary conditions, error paths, and normal operation, aiming for high code coverage. In practice, a failure in unit testing can reveal logic errors early, reducing the cost of defects that would otherwise be found during integration or system testing.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
A practitioner preparing for the CISA exam encounters this exact type of scenario on the job. The correct answer here is not the most general option — it is the best answer for the specific constraint described. Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option. Real exam questions reward reading the full scenario before eliminating options, because the constraint defines which answer fits.
What to study next
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
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FAQ
Information Systems Acquisition, Development and Implementation — This question tests Information Systems Acquisition, Development and Implementation — Read the scenario before looking for a memorised answer..
The correct answer is: Unit testing — Unit testing is the phase where developers test individual program units or modules in isolation to verify they function correctly according to their design specifications. This is the lowest level of testing and is typically performed using stubs and drivers to simulate interfaces with other components.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Read the scenario before looking for a memorised answer.
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Last reviewed: Jun 25, 2026
This CISA practice question is part of Courseiva's free ISACA certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the CISA exam.
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