Which line from the output of the show ip interface command indicates that there is a Layer 1 problem?A．Serial0/1 is up, line protocol is downB．Serial0/1 is down, line protocol is downC．Serial0/1 is up, line protocol is upD．Serial0/1 is administratively d

Which line from the output of the show ip interface command indicates that there is a Layer 1 problem?

A．Serial0/1 is up, line protocol is down

B．Serial0/1 is down, line protocol is down

C．Serial0/1 is up, line protocol is up

D．Serial0/1 is administratively down, line protocol is down

E．None of the above