Which testing approach is performed without prior knowledge of the internal workings of the system?

• A. Black-Box Testing
• B. White-Box Testing
• C. Gray-Box Testing
• D. Unit Testing

Answer: (A)

Testing without prior knowledge of a system's internal workings focuses on external behavior—the inputs you give and the outputs or responses you receive, as defined by requirements. This is the approach where you don’t look at code, architecture, or internal logic; you validate that the system behaves correctly from an end-user or API perspective. By concentrating on what the system should do, you uncover issues like missing features, incorrect handling of inputs, or mismatches between the specifications and what’s delivered.

In contrast, white-box testing relies on knowing the internal structure to design tests that exercise specific code paths. Gray-box testing uses partial internal knowledge, and unit testing targets individual components with awareness of their implementation. So, the option described here best matches black-box testing.