Which term refers to a unique identifier embedded permanently into a NIC?

• A. MAC Address
• B. MT-RJ Connector Fiber
• C. Modem
• D. Mesh Physical Topology

Answer: (A)

This tests the concept of a hardware-embedded identifier assigned to a network interface. A NIC has a MAC address, a unique hardware address burned into the device by the manufacturer. This identifier is used at the data link layer to identify the device on a local network and is intended to be permanent, though software can sometimes override it for purposes like spoofing.

Why this is the best answer: The term described is a unique identifier that is permanently embedded in the NIC itself, precisely what a MAC address is. It enables proper frame delivery and filtering in Ethernet and Wi‑Fi networks.

Why the others don’t fit: MT-RJ Connector Fiber is simply a fiber optic connector type, not an identifier. A modem is a device that modulates and demodulates signals for communication. Mesh Physical Topology describes how devices are interconnected, not a hardware identifier.