Your network contains one Active Directory domain named contoso.com.
The domain contains the domain controllers configured as shown in the following table.
The functional level of the domain and the forest is Windows Server 2008. An administrator named Admin1 is a member of the Domain Admins group. You need to ensure that Admin1 can deploy a Windows Server 2012 R2 domain controller to contoso.com.
What should you do?
A . Raise the forest functional level.
B . Run the Set-ADForestMode cmdlet.
C . Run the adprep.exe command.
D . Upgrade DC1 to Windows Server 2012.
Answer: C