You have an Active Directory forest that contains one domain named contoso.com. The functional level of both the forest and the domain is Windows Server 2003. You have an Exchange Server 2003 organization. All servers have Exchange Server 2003 Service Pack 2 （SP2） installed. You plan to transition to Exchange Server 2010. You need to prepare the Active Directory environment for the deployment of the first Exchange Server 2010 server.  What should you run（）？ 

• A、Setup.com /PrepareAD
• B、Setup.com /PrepareDomain
• C、Setup.com /PrepareLegacyExchangePermissions
• D、Setup.com /PrepareSchema