Your network contains an Active Directory forest named contoso.com. The functional level of the forest is Windows Server 2008 R2. The forest contains a single domain.

You need to ensure that objects can be restored from the Active Directory Recycle Bin.

Which tool should you use?

A.
Ntdsutil

B.
Set-ADDomain

C.
Dsamain

D.
Enable-ADOptionalFeature

Explanation:
http://technet.microsoft.com/en-us/library/dd379481%28v=ws.10%29.aspx