Your company has a main office and a branch office.  The network contains a single Active Directory domain.  The main office contains a domain controller named DC1.   You need to install a domain controller in the branch office by using an offline copy of the Active Directory  database.   What should you do first（）

• A、From the Ntdsutil tool， create an IFM media set.
• B、From the command prompt， run djoin.exe /loadfile.
• C、From Windows Server Backup， perform a system state backup.
• D、From Windows PowerShell， run the get-ADDomainController cmdlet.