A software solution must be deployed based on the most granular access level. Which of the following methods should be used to meet the requirements?

Group-based access assigns a shared set of permissions to all members of a group, which is coarser than RBAC because it does not differentiate access by functional role or allow fine-grained permission scoping within a group.

RBAC defines roles with precisely scoped permissions and assigns users to those roles, allowing administrators to enforce least-privilege access at a fine-grained level across users, resources, and actions - providing more specificity than flat group membership, file-level controls, or directory protocols alone.

File-based access control governs permissions at the individual file or resource level and does not provide a structured, system-wide framework for defining and managing granular user access across an entire application.

LDAP is a directory service protocol used for storing and querying user and group information, not an access control enforcement mechanism capable of independently defining or applying granular permissions.