Routers R2 and R4 Are Directly Connected on Their Serial1

Multiple Choice

Routers R2 and R4 are directly connected on their serial1 interfaces using a DTE / DCE cable. R2 is using HDLC encapsulation and R4 is using PPP. David runs a "show interface serial1" on both of the routers. What will be the command output show?

A) A message states, "Serial 1 is up, line protocol is down."
B) A message states, "Serial 1 is administratively down, line protocol is down."
C) A message states, "Serial 1 is down, line protocol is down."
D) A message states, "Serial 1 is up, line protocol is up."