You create a Web site that is for members only. The behavior of the Web site changes according to the role of the user. The Web site uses the ASP.NET Membership control for creation of user accounts. You need to find out whether a user is a member of a particular role. What should you do?（）

A. Pass the user names and passwords to Membership.ValidateUser.
B. Pass the role names to User.IsInRole.
C. Pass the role names to Roles.RoleExists.
D. Pass the user names to Membership.GetUser.