Which key performance efficiency IKPI) BEST measures the effectiveness of an organization's disaster recovery program?

 The key performance indicator (KPI) that best measures the effectiveness of an organization’s disaster recovery program is the percentage of critical systems recovered within the recovery time objective (RTO). The RTO is the acceptable timeframe within which a business process or system must be restored after a disruption. The percentage of critical systems recovered within the RTO indicates how well the disaster recovery program can meet the business continuity requirements and minimize the impact of the disruption. The other options are not as good as the percentage of critical systems recovered within the RTO, as they are related to the efficiency, quality, or scope of the disaster recovery program, not the effectiveness of the disaster recovery program. References = Risk and Information Systems Control StudyManual, Chapter 4: Risk and Control Monitoring and Reporting, Section 4.2: Key Performance Indicators, page 183.