What should you do?

Your network contains a single Active Directory domain. The functional level of the domain is Server 2003. The domain contains the following server:
Ten servers that run Windows Server 2003
Twenty servers that run Windows Server 2008
One server that has Microsoft Exchange Server 2007 installed
One server that has System Center 2012 Configuration Manager installed

Users have mobile devices that run Windows Mobile 6.5 and Windows Phone. You need to ensure that you can manage the settings of the mobile devices and perform remote device wipes by using Configuration Manager. What should you do?

A.
Upgrade the Exchange server to Exchange Server 2010. Configure an Exchange connector.

B.
Change the functional level of the domain to windows 2008. Upgrade the Exchange server to Exchange Server 2010.

C.
Upgrade all Windows 2003 domain controllers to Windows 2008.

D.
Upgrade all of the domain controllers to Windows 2008 R2. Configure an Exchange connector.