The output of a show interfaces command on the router displays the following status for serial 0/0: line status up; protocol status down. Which of the following could this indicate? A. There is a bad...

The output of a show interfaces command on the router displays the following status for serial 0/0: line status up; protocol status down. Which of the following could this indicate?

A. There is a bad cable connection to the serial port.

B. The shutdown command has been configured on the interface.

C. The interface can pass traffic, but there is a speed or duplex problem.

D. HDLC is configured on this interface while PPP is configured on the other end of the connection.