Your network contains a single Active Directory domain. The domain contains five read-only domain   controllers （RODCs） and five writable domain controllers. All servers run Windows Server 2008.  You plan to install a new RODC that runs Windows Server 2008 R2.   You need to ensure that you can add the new RODC to the domain. You want to achieve this goal by using the minimum amount of administrative effort.   Which two actions should you perform（）

• A、At the command prompt， run adprep.exe /rodcprep.
• B、At the command prompt， run adprep.exe /forestprep.
• C、At the command prompt， run adprep.exe /domainprep.
• D、From Active Directory Domains and Trusts， raise the functional level of the domain.
• E、From Active Directory Users and Computers， pre-stage the RODC computer account.