Which of the following is NOT a key function of BIOS?

The correct answer is D, as controlling network traffic is not a function of BIOS. BIOS, or Basic Input/Output System, primarily operates at a lower level to initialize and manage hardware components during the boot process of a computer.

BIOS is responsible for activating the system devices, testing them via POST (Power-On Self Test), and identifying the system devices. This initialization ensures that the hardware is working correctly and prepares the system to load the operating system. However, managing or controlling network traffic is a function that occurs at a higher level within the network stack, typically handled by the operating system and network drivers, rather than by the BIOS itself.