Which statement best describes gray-box testing?

• A. Tester has full knowledge of source code
• B. Internal operations are completely hidden from tester
• C. Internal operation is partly accessible to the tester
• D. Testing focuses solely on user experience

Answer: (C)

Gray-box testing blends some knowledge of a system’s internals with external testing. The tester has partial visibility into internal processes, data structures, or design while still evaluating the system from an outside perspective. This partial access lets you target specific components or controls without needing full source-code access, which is exactly what the statement describes: internal operation is partly accessible to the tester.

Having full knowledge of the source code would be white-box testing, where the tester reviews internal logic and code paths. If internal operations were completely hidden, you’d be dealing with black-box testing. If the focus were solely on how users interact with the system, that would be usability testing, not gray-box testing.