What type of software testing is generally used in Software Maintenance?OptionsRegression TestingIntegration TestingUnit TestingSystem Testing

In the context of software maintenance, the type of testing that is generally most applicable is Regression Testing.

Explanation:

1. Regression Testing is performed to ensure that recent changes in the code, such as bug fixes or new features, have not adversely affected the existing functionalities of the software. This is crucial during maintenance phases since modifications are often implemented to improve or adapt the software, and it’s essential to verify that previously developed and tested features still operate correctly.

2. Integration Testing focuses on verifying the interactions between integrated components or systems, which might not be the primary focus during a maintenance phase unless changes affect multiple modules.

3. Unit Testing is generally performed during the development phase to test individual components. It's less common during maintenance unless specific modules are rewritten or new modules are added.

4. System Testing evaluates the complete system to ensure it meets the specified requirements. While important, its primary function isn't targeted specifically at ongoing maintenance but rather at ensuring full compliance at each release stage.

In summary, Regression Testing is the preferred answer, as it directly aligns with ensuring that existing functionalities remain intact after maintenance activities.