What does UEFI stand for?

UEFI stands for Unified Extensible Firmware Interface. This specification defines a software interface between an operating system and platform firmware, replacing the older BIOS system that was traditionally used. UEFI offers a number of advantages over BIOS, including faster boot times, support for large hard drives (over 2 TB), and enhanced security features such as Secure Boot, which helps prevent unauthorized firmware, operating systems, or applications from loading during the startup process. By standardizing the pre-boot environment, UEFI allows operating systems to interact with the hardware more efficiently and opens up the potential for advanced features not possible with the traditional BIOS architecture.

The other options do not accurately reflect the commonly accepted terminology used in the industry.