What access control methodology would allow a manager to determine the conditions under which personnel can access systems?

The correct choice focuses on discretionary access control (DAC), which is a methodology that allows users to make decisions regarding their own access to resources. In DAC, the owner of the resource or an object can decide who is permitted to access it, and under what conditions. This flexibility is essential in environments where a manager needs the ability to set specific conditions or policies for personnel accessing systems.

This methodology is particularly beneficial because it enables managers to tailor access rights to individual users or groups, meaning they can specify time-of-day access, geographical access, or other contextual conditions based on the organization's needs. This individualized control supports a dynamic and responsive security posture, aligning access to varying operational requirements or situational factors.

In contrast, role-based access control (RBAC) assigns permissions based on predefined roles rather than on individual user discretion. Mandatory access control (MAC) enforces a stricter policy determined by the system, where access decisions are made based on security levels and classifications. Defense-in-depth, while a valuable security principle, refers to layering multiple security measures and does not specifically pertain to defining access conditions for personnel.