The correct option is Activation phase.

The Activation phase is the stage in which the disaster recovery procedures are actually put into motion. In this phase the organization declares the disaster, executes the recovery playbooks, performs failover to alternate sites or systems, and coordinates the teams responsible for restoring operations.

Planning phase is incorrect because that stage involves developing the disaster recovery plan and identifying resources and roles rather than executing recovery actions.

Implementation phase is incorrect because that stage refers to deploying controls and infrastructure or putting the plan elements in place rather than activating the plan in response to an actual incident.

Testing phase is incorrect because that stage is used to validate and rehearse the plan through exercises and drills rather than to perform the real failover and production recovery when a disaster is declared.

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