单选题
The X.25 standard specifies three layers of functionality. Which layers of the OSI model correspond to the X.25 layers?
A、
the Physical, Network, and Session Layers
B、
the Physical, Data Link, and Network Layers
C、
the Physical, Data Link, and Transport Layers
D、
the Physical, Session, and Presentation layers
【正确答案】
B
【答案解析】
提交答案
关闭