单选题 (73) is a six bytes OSI layer 2 address which is burned into every networking device that provides its unique identity for point to point communication。

A、 The virtual address
B、 The subnet address
C、 The MAC address
D、 The IP address

【正确答案】 C

【答案解析】[参考译文] MAC地址是一个OSI第2层(即数据链路层)6个字节的地址，提供点对点通信时唯一地标识每个网络设备。