Your network contains an Active Directory forest. All domain controllers run Windows Server 2008. You need to ensure that you can install an Exchange Server 2010 server in the Active Directory forest.  What should you do（）？ 

• A、From the Exchange Server 2010 installation media， run setup /ps.
• B、From the Exchange Server 2010 installation media， run setup /NewProvisionedServer.
• C、From the Windows Server 2008 installation media， run adprep.exe /forestprep.
• D、From the Windows Server 2008 installation media， run adprep.exe /domainprep.