Final answer:
Guards are the most appropriate physical security control when discriminating judgment is required for maintaining physical security of a facility.
Step-by-step explanation:
The most appropriate physical security control when discriminating judgment is required for maintaining physical security of a facility is guards. Guards have the ability to assess situations, use discretion, and exercise judgment based on the specific needs of the facility and the surrounding environment. They can adapt to different situations and address potential security breaches in real-time.