Which macOS security feature encrypts the entire macOS volume?

TheCCST Cybersecurity Study GuidehighlightsFileVaultas the macOS full-disk encryption tool.

"FileVault is macOS’s built-in full-disk encryption feature. It encrypts the contents of the entire startup disk to help prevent unauthorized access to the information stored on the drive, even if the device is lost or stolen."

(CCST Cybersecurity,Endpoint Security Concepts, Disk Encryption section, Cisco Networking Academy)

Ais correct: FileVault provides complete volume encryption.

B(Gatekeeper) controls app installation by verifying code signatures.

C(System Integrity Protection) protects system files from modification.

D(XProtect) is macOS’s built-in malware detection system.