To answer this question, you need to understand regression testing. Let's go through each option to understand why it is correct or incorrect:
Option A) Regression testing is run ONLY once - This option is incorrect because regression testing is not limited to a single execution. It is typically performed multiple times throughout the software development lifecycle to ensure that previously working functionality has not been impacted by recent changes.
Option B) Regression testing is often automated - This option is correct. Regression testing is frequently automated to save time and effort. By automating the tests, they can be executed quickly and repeatedly, making it easier to detect any regressions.
Option C) Regression testing is used after fixes have been made - This option is correct. Regression testing is performed after fixes or changes have been made to the software. Its purpose is to ensure that the modifications have not introduced any new defects or caused any existing functionality to break.
Option D) Regression tests need not be maintained - This option is incorrect. Regression tests do need to be maintained. As the software evolves, new features are added, and existing features are modified. Consequently, the regression tests must also be updated to reflect these changes and ensure that they continue to accurately test the relevant functionality.
The correct answer is C. Regression testing is used after fixes have been made. This is because regression testing is designed to verify that the fixes or changes made to the software have not introduced any new defects or caused any existing functionality to break.