The SetRecoveryLock command locks the Recovery partition, restricting access to Startup Security Utility. The Mobile Device Management Protocol Reference states, "The SetRecoveryLock command sets a password for the Recovery partition, restricting access to Startup Security Utility and other recovery options unless the password is provided." Option B sets a firmware password but not specifically for this utility, and C and D are invalid.
Reference:
Mobile Device Management Protocol Reference, "SetRecoveryLock" section.
macOS Security Overview, "Recovery Lock" section.