Which VPN technology is the most common and the easiest to set up?

A.
PPTP

B.
L2TP with IPSec

C.
SSTP

D.
CHAP

Explanation:
Section Reference: Understanding VPNs
Point-to-Point Tunneling Protocol (PPTP) is the more commonly used protocol, but it is also the less secure
option. PPTP generally includes security mechanisms, and no additional software or protocols need to be
loaded.