You work as an IT professional in an international corporation named Wiikigo. In the company, your job is to configure Microsoft Internet Security and Acceleration Server 2006. And you are experienced in performing and managing networks and operational systems. In addition, you are skilled at deploying ISA Server 2006, configuring firewall settings, and optimizing performance of the ISA Server 2006 cache. There is a VPN server in the company network. ISA Server 2006 is run by this VPN server. According to the company requirement, two-factor authentication for VPN access should be implemented. Since you are the technical support, the company assigns this task to you. You have to decide the authentication protocol which will support your planned implementation. So which authentication method should be choosed?

A.
Extensible authentication protocol (EAP) with smart card or other certificate should be choosed.

B.
Unencrypted password (PAP) should be choosed.

C.
Encrypted authentication (MS-CHAP) should be choosed.

D.
Microsoft encrypted authentication version 2 (MS-CHAPv2) should be choosed.