Which of the following is not a type of incremental testing approach?

The big-bang testing approach is not considered an incremental testing approach. In big-bang testing, all components or modules are integrated and tested simultaneously after the completion of the entire development phase. This means that testing starts only after all parts of the system are developed, which does not allow for any incremental testing of components as they are completed.

On the other hand, incremental testing approaches such as top-down, bottom-up, and functional incrementation involve the gradual integration and testing of components or features. In top-down, testing begins with higher-level components and gradually works down to lower-level components, while bottom-up starts with lower-level components and integrates upwards. Functional incrementation focuses on adding functional features incrementally and testing each addition as it occurs. These approaches are beneficial because they allow for earlier detection of defects and more manageable testing efforts.