A. Antivirus: Protects against malware and viruses.

B. Encryption: Secures data by making it unreadable to unauthorized users.

C. Firewall: Monitors and controls incoming and outgoing network traffic based on security rules.

D. Firmware: While it can have security features, it is primarily the software that controls hardware. It does not directly prevent security breaches by itself.

Therefore, Option D is correct.