正解:A
Executive sponsorship (A) is the most critical factor for the long-term success of an information security program. CISM emphasizes that leadership support enables funding, enforcement, cross-functional cooperation, and cultural adoption. Skilled staff (B), automation (C), and training (D) are important but depend on sustained executive backing to remain effective. Without sponsorship, security initiatives often lack authority and momentum.
References: ISACA CISM Review Manual (Governance-leadership and sponsorship); CISM Exam Content Outline (Domain 2).