Explanation
The best way to restrict access to a set of sensitive files to a specific group of users is to change the file permissions and ownership of the files. File permissions and ownership are attributes that determine who can read, write, execute, or modify the files. By changing the file permissions and ownership, the systems administrator can grant or deny access to the files based on the user identity or group membership.
Reference: CompTIA Cloud+ Certification Exam Objectives, Domain 2.0 Security, Objective 2.3 Given a scenario, implement appropriate access control measures for a cloud environment.