In white-box testing, what does control flow testing primarily verify?

• A. It ensures syntax correctness only.
• B. It ensures that all paths through the code are tested.
• C. It ensures memory usage is minimized.
• D. It ensures that only the most frequently executed paths are tested.

Answer: (B)

In white-box testing, control flow testing focuses on how the program’s execution moves through statements, branches, and loops. Its purpose is to exercise all possible paths that the code can take, ensuring every decision point is tested and that there isn’t dead or unreachable code. This approach helps reveal logic errors in branching and looping constructs that might be missed by tests that don’t probe the different paths. So the best choice is the one that emphasizes testing every path through the code, not just syntax, memory usage, or a subset of paths.