Which activities are performed to test the release of an application before deploying to production?

Regression testing is the correct answer because it specifically focuses on ensuring that recent changes or updates to the application do not adversely affect the existing functionality. This type of testing is crucial prior to deploying the application to production, as it helps identify any new bugs that may have been introduced during development or adjustments, assuring that all existing features continue to work as expected.

During regression testing, testers execute a suite of test cases that cover both new and existing functionalities. This process is vital to maintain the integrity and quality of the application after updates, thereby minimizing the risk of issues arising in the production environment. By performing rigorous regression testing, organizations can confidently deploy new versions of their applications knowing that they have mitigated potential risks related to changes.

User training, data migration, and configuration management, while essential aspects of the overall deployment process, serve different purposes that are not directly aligned with the testing of application releases. User training focuses on preparing end-users to effectively use the application, data migration involves transferring existing data to the new system, and configuration management deals with maintaining system integrity and monitoring changes. These activities, while necessary for a successful deployment, do not fundamentally address the need to validate that the application functions correctly after changes, which is why regression testing stands out as the key