正解:C
In the context of Business Continuity/Disaster Recovery (BC/DR), the activity that includes actions taken toward resuming all services that are dependent on business-critical applications is referred to as Resumption. This phase focuses on the steps necessary to bring critical functions back into operation after a disruption. Recovery, on the other hand, is more about the actions taken to return the business to normal operating conditions post-disaster, which may include repairs, restorations, and return to normalcy. Response is the immediate reaction to an incident, and Restoration is the process of rebuilding or restoring IT systems and operations. Reference: The information aligns with the objectives and documents of the EC-Council's Certified Network Defender (CND) program, which emphasizes understanding and implementing proper BC/DR activities.