Which records are used to verify that a program functions properly?

• A. Changelogs
• B. Log files
• C. User manuals
• D. Test files

Answer: (D)

Testing relies on controlled inputs and expected outcomes to confirm a program behaves correctly. Test files provide concrete input data and the expected results, which you run through the software to verify that its functions return the right outputs, handle edge cases, and meet requirements. They’re the practical tools used during development and quality assurance to prove the program works as intended. Changelogs show what changed between versions, not whether the current version functions properly. Log files record what happened during execution and help with debugging, but they don’t serve as primary evidence of correct behavior. User manuals describe how to use the software, not whether it operates correctly. So, test files are the records you use to verify proper function.