A network administrator uses GRE over IPSec to connect two branches together via VPN
tunnel. Which one of the following is the reason for using GRE over IPSec?

A.
GRE over IPSec provides better QoS mechanism and isfaster than other WAN
technologies.

B.
GRE over IPSec decreases the overhead of the header.

C.
GRE supports use of routing protocol, while IPSec supports encryption.

D.
GRE supports encryption, while IPSec supports use of routing protocol.