Computer Science - Windows 2000 Server - Discussion

You enable the Routing and Remote Access Service (RRAS) on a computer running Windows 2000 Server. You configure the computer as a RAS server. You want to provide mutual authentication between the RAS server and RAS clients. You also want to ensure that data passing between the RAS server and RAS clients is encrypted. Which authentication method should you use for your incoming connections to support mutual authentication and data encryption?