Differentiate between DAC, MAC, and RBAC.

• A. RBAC grants access based on defined job roles.
• B. DAC lets owners grant access at the discretion of resource owner; MAC enforces system-wide policies regardless of user desire; RBAC grants access based on defined job roles.
• C. RBAC is discretionary; DAC is role-based; MAC is user-based.
• D. DAC lets owners grant access at the discretion of resource owner.

Answer: (B)

Access control models describe who can do what with resources and how those permissions are determined and enforced. In Discretionary Access Control, the owner of a resource decides who can access it and what they can do, often by assigning permissions directly. In Mandatory Access Control, access is governed by centralized, system-wide policies; permissions come from labels or clearances, not the owner's wishes, ensuring consistent control across the system. In Role-Based Access Control, permissions are tied to roles defined by the organization, and users gain access by being assigned to those roles.

This is why the described combination is the best: DAC emphasizes owner discretion, MAC emphasizes centralized policy enforcement, and RBAC emphasizes role-based permissions. The other descriptions are incomplete or mix up the models, making them less accurate.