Comprehensive and Detailed Explanation: Fault tolerance refers to the ability of a system to continue functioning despite the occurrence of faults or hardware failures. * Option A: Describes failover, not fault tolerance. * Option B: Is a benefit but not the exact definition. * Option D: Refers to load balancing, not fault tolerance. # ISACA Reference: CISA Review Manual 27th Edition, Domain 2, section on system availability, resilience, and fault tolerance.