Your network consists of a Windows Server 2003 Active Directory forest that contains a Windows Server 2003 enterprise certification authority (CA). You have an Exchange Server 2003 organization. Users access their mailboxes by using Windows Mobile 5.0 and Windows Mobile 6.1 devices. You plan to transition the organization to Exchange Server 2010. You need to plan a certificate solution for the Exchange Server 2010 deployment. The solution must minimize the amount of effort required to connect all mobile devices to the organization.

What should you include in the plan?

A.
Create a self-signed certificate and install it on the Client Access server.

B.
Obtain a wildcard certificate from a trusted third-party CA and install it on the Client Access server.

C.
From an internal CA, obtain a certificate that contains multiple names and install it on the Client Access server.

D.
From a trusted third-party CA, obtain a certificate that contains multiple names and install it on the Client Access server.