A unique address assigned to NICs by manufacturers for identification is called a ____.

• A. Internet Protocol address
• B. Unicast address
• C. Ethernet address
• D. Media Access Control address

Answer: (D)

The concept here is the unique hardware identifier built into a network interface card. This identifier is the MAC address—Media Access Control address—which is assigned by the NIC manufacturer and stored on the card. It serves to uniquely identify that specific device on a local network at the data-link layer, allowing frames to be delivered to the correct NIC regardless of higher-layer addresses. IP addresses, by contrast, are logical identifiers configured by software or network services and can change. While some people use the term Ethernet address to refer to the same hardware identifier, the formal, widely used name is Media Access Control address, making it the best choice.