Your network contains an Active Directory domain named contoso.com. The domain contains a domain
controller named DC5. DC5 has a Server Core Installation of Windows Server 2012 R2.
You need to uninstall Active Directory from DC5 manually.
Which tool should you use?

A.
The dsamain.exe command

B.
The ntdsutil.exe command

C.
The Remove-ADComputer cmdlet

D.
The Remove-WindowsFeature cmdlet

Explanation:
The Remove-ADComputer cmdlet removes an Active Directory computer.
Example: Remove-ADComputer -Identity “FABRIKAM-SRV4”
Remove one particular computer.

http://technet.microsoft.com/en-us/library/ee662310.aspx
http://support.microsoft.com/kb/216498
http://technet.microsoft.com/en-us/library/ee617250.aspx