Which of the following is not a simulation but would be an option for actually performing an active failover to test disaster recovery capabilities?

In the context of disaster recovery capabilities, the active failover is a process that involves switching over to a backup system or site to maintain operations without interruption. This is a real, operational activity rather than a simulation, which aligns with the need to actually test and validate how systems respond in the event of a failure.

In contrast, checklists, tabletop exercises, and walk-throughs are all methods used in planning and training for disaster recovery but do not involve actual failover to a secondary system. Checklists serve as guides to ensure that all necessary steps are considered during a recovery process, tabletop exercises provide a forum to discuss and simulate response scenarios in a controlled setting, and walk-throughs allow teams to verbally go through the recovery procedures without executing them. Therefore, while each of these methods contributes to preparedness, they do not involve the actual performance of an active failover, making them distinct from the true operational testing that an active failover entails.