The best protection against physical threats, especially in a common area where the computer is publicly accessible, involves physically securing the hardware. * Option A: Using screen lockScreen locks are good for securing access temporarily but do not protect against physical tampering or theft. * Option B: Installing a privacy screenPrivacy screens prevent visual access but do not secure the hardware. * Option C: Implementing password complexityPassword complexity helps secure digital access but does not prevent physical threats. * Option D: Locking the computer casePhysically securing the case prevents unauthorized individuals from tampering with internal components or stealing the computer. * Option E: Enabling drive encryptionEncryption protects data but does not prevent physical access to the hardware itself. References: * CompTIA A+ 220-1102 Objective 2.1 (Physical security), particularly physical security measures like locking the computer case.