A business continuity plan (BCP) relies on clear roles and responsibilities to ensure effective execution during a disruption. The CGEIT Review Manual 8th Edition emphasizes that defined roles are the most critical component for BCP success, as they ensure accountability and coordination.

Extract from CGEIT Review Manual 8th Edition (Domain 3: Risk Optimization):"The most important element for executing a business continuity plan is the definition of roles and responsibilities. Clear roles ensure that all stakeholders know their duties during a disruption, enabling rapid and coordinated response." (Approximate reference: Domain 3, Section on Business Continuity Planning)

Defined roles (option A) are essential to ensure that the BCP is actionable, with individuals assigned to specific tasks, such as communication, recovery, or coordination.

Why not the other options?

B. Replicated systems: Systems are important but useless without people to manage them during a crisis.

C. A risk register: A risk register identifies risks but does not ensure BCP execution.

D. Budget allocation: Funding supports BCP development but is not the most critical for execution.