While logged into a router you manually shut down the serial 0 interface using the "shutdown" interface configuration command. You then issue the "show interface serial 0" command in exec mode. What could you expect the status of the serial 0 interface to be?（）
- A Serial 0 is up, line protocol is up
- B Serial 0 is up, line protocol is down
- C Serial 0 is down, line protocol is down
- D Serial 0 is down, line protocol is up
- E Serial 0 is administratively down, line protocol is down
- F Serial 0 is administratively down, line protocol is u