The correct answer is B. Rights and privileges. CompTIA DataSys+ clearly distinguishes between different categories of security controls, and access to shared resources such as folders is governed primarily by authorization mechanisms, specifically rights and privileges. In this scenario, access is restricted so that only authorized users can view or modify the shared folder, which directly reflects the enforcement of permissions.

Rights and privileges define what actions an authenticated user is allowed to perform on a system or resource. For shared folders, this typically includes read, write, modify, or full control permissions assigned to users or groups. DataSys+ emphasizes the principle of least privilege, which ensures users are granted only the minimum level of access required to perform their job functions. Applying appropriate rights and privileges protects sensitive data from unauthorized access and accidental modification.

Option A, password policies, control how passwords are created and managed, such as complexity, expiration, and reuse rules. While password policies help verify a user’s identity during authentication, they do not determine which resources a user can access after logging in. Option C, service accounts, are specialized non-human accounts used by applications or services and are unrelated to user access to shared folders. Option D, firewall policy, controls network-level traffic and determines which connections are allowed or blocked between systems, not access to files or folders once a connection is established.

CompTIA DataSys+ materials emphasize that security is layered, with authentication confirming identity and authorization enforcing access. In this case, users are already authenticated, and the restriction applies at the resource level. That makes rights and privileges the relevant control.

Therefore, the policy applied to ensure only authorized users can access the shared folder is rights and privileges, making option B the correct and fully verified answer.