You are creating an XML Web service named myWebService. This service will be used to exchange highly confidential information over the Internet with your company’s business partner named Fabrikam, Inc. You want only callers from Fabrikam, Inc., to be able to access myWebService. You do not want to have to accept a user name and password from callers. Once callers are authenticated, you want to use Windows user accounts to authorize access to the Web methods exposed by the Web service. You set up two Windows user accounts named FabrikamAssociate and FabrikamManager. You need to configure myWebService to meet these security requirements. Which type of authentication should you use?

A.
Basic

B.
Digest

C.
Anonymous

D.
Client Certificate