Final answer:
The recommended security solution for a PC technician to protect a dental clinic's computer from bootable disks with hacking tools is Secure Boot.
Step-by-step explanation:
Security Solution Recommendation
To protect a computer at a dental clinic from unauthorized access using a bootable disk containing hacking tools, the technician should recommend Secure Boot. Secure Boot is a security standard developed by members of the PC industry to ensure that a device boots using only software that is trusted by the Original Equipment Manufacturer (OEM). When enabled, the computer's firmware checks the signature of each piece of boot software, including drivers and the operating system, against a database of signatures authorized by the OEM. If the signatures do not match, the system will not boot.
Other options such as biometric authentication, encryption, and multi-factor authentication are valuable security measures, but they do not directly address the threat of a bootable disk containing hacking tools. For this specific scenario, Secure Boot would be most effective in preventing unauthorized booting from an external device containing potentially harmful software.