Which statement describes the HDLC protocol?

A.
HDLC is compatible between all network vendors.

B.
HDLC utilizes sophisticated flow control mechanisms to ensure reliable data transfer.

C.
On Cisco routers it is the default encapsulation for serial interfaces.

D.
It is the preferred protocol for LAN communication.

E.
The Cisco implementation of HDLC does not include proprietary extensions.

Explanation: