You have Microsoft Office SharePoint 2007 Server farm that has a Single Sign-On implementation. You plan to deploy a web part that will access data through a web service. The web service and the web part are in different web applications. The web service uses a custom authentication provider.

To ensure that users are not prompted to enter credentials when they access the web part, what should you do?

A.
Implement the ISSOProvider Interface and the GetCredentials method

B.
Implement the iAuthenticationModule interface and the Authentication method

C.
Inherit the SOAPHeaderAttribute and then set the member name property

D.
Inherit the SOAPExtension class and then override the Process method