MCSA XP

Answer - A - Password Authentication Protocol or PAP does not support encryption. Hence, it is more vulnerable to attack than other protocols and must be used only when the remote access client does not support any other method of authentication.

Key Takeaway: PAP transmits unencrypted ASCII passwords over the network. It is used as a last resort, when the remote server does not support a stronger authentication protocol, like CHAP or EAP.