Which statement is correct regarding the configuration of a serial link on a Cisco router?

Which statement is correct regarding the configuration of a serial link on a Cisco router?

A.
Cisco routers are DCE devices.

B.
The clock rate command is a requirement for DCE interfaces.

C.
The bandwidth command guarantees maximum bandwidth during congestion.

D.
If the clock rate command is configured, then the bandwidth command is required.

E.
If the bandwidth command is configured, then the clock rate command is required.

Explanation: