正解:A
A risk-based approach (A) is fundamental to control design in CISM. Controls must be proportionate to risk, aligned with business objectives, and consistent with risk appetite. Focusing solely on technical controls (B), BIA results (C), or preventive controls (D) limits effectiveness. A risk-based approach ensures balanced use of preventive, detective, and corrective controls.
References: ISACA CISM Review Manual (Risk management-control selection); CISM Exam Content Outline (Domain 1).