Which of the following is the method of black box testing ?

Black box testing evaluates software functionality without examining internal code structures, focusing solely on inputs and outputs. Boundary value analysis is a classic black box technique because it tests the edges of input domains (e.g., minimum, maximum values) to detect errors at boundaries where bugs often occur. This method relies entirely on specifications rather than code logic.\nIn contrast, basic path testing and code path testing are white box techniques. They require knowledge of the internal logic flow, control structures, and code paths to design test cases. Since these methods depend on inspecting the source code, they do not qualify as black box testing approaches. Therefore, boundary value analysis is the only correct option among those listed.