Explanation
Choice A represents the primary driver for the information security manager to make use of external resources.
The information security manager will continue to be responsible for meeting the security program requirements despite using the services of external resources. The external resources should never completely replace the role of internal resources from a strategic perspective. The external resources cannot have a better knowledge of the business of the information security manager's organization than do the internal resources.

The needs of the organization define the triggers within a business continuity plan (BCP). Triggers are the events or conditions that initiate the activation of the BCP. The triggers should be based on the organization's business objectives, risk appetite, recovery time objectives, and recovery point objectives. The triggers should also be aligned with the organization's information security policy, disaster recovery plan, and gap analysis. However, these are not the primary factors that define the triggers, but rather the supporting elements that help implement the BCP. The needs of the organization are the main drivers for determining the triggers, as they reflect the organization's priorities, expectations, and requirements for business continuity. Reference = CISM Review Manual (Digital Version) 1, Chapter 4: Information Security Incident Management, pages 191-192, 195-196, 199-200.
Business Continuity Management Guideline 2, page 5, Section 4.2.1: Triggers Business Continuity Plan - Open Risk Manual 3, page 1, Section 1: Introduction