Which of the following tunneling protocols would be used if tunneled communication needed to take place over IPX, ATM, or frame relay?

A.
PPTP

B.
L2TP

C.
IPSec

D.
PPP

Explanation:
L2TP can tunnel through networks that incorporate many types of
protocols, such as X.25, ATM, and frame relay. PPTP and IPSec can only work over
IP-based networks. L2TP does not provide any encryption and must be combined with
IPSec if this type of protection is needed. L2TP was developed by combining the best
of the L2F and PPTP protocols.