Q3 /20 What is white box testing?

White box testing (also called glass box or clear box testing) involves testing with full knowledge of the internal code structure, logic, and implementation. The tester understands not just the inputs and outputs, but also the technical methods, algorithms, and code paths between them. This includes unit testing, integration testing at the code level, and path coverage analysis. Options B and C both correctly capture this definition, while A is incomplete (ignores outputs and internals) and D is absurd (confuses physical color with testing methodology).

Step-by-step Derivation:
White box testing is a software testing technique where the tester has complete visibility into the application's internal structure, source code, and logic. Key characteristics: (1) Requires knowledge of programming languages and code logic, (2) Tests internal code paths, branches, and conditions, (3) Enables unit testing and code coverage analysis, (4) Covers inputs, outputs, AND the implementation details in between. Option B explicitly states understanding inputs, outputs, AND technical methods—the complete definition. Option C correctly identifies it as testing with code knowledge and gives unit testing as a valid example. Both B and C are correct; A is incomplete, and D is a distractor with no relevance.