Your network contains an Active Directory domain named contoso.com. The domain contains domain controllers that run Windows Server 2008 Service Pack 2 (SP2), Windows Server 2008 R2 Service Pack 1 (SP1), Windows Server 2012, and Windows Server 2012 R2. A domain controller named DC1 runs Windows Server 2012 R2. DC1 is backed up daily. During routine maintenance, you delete a group named Group1. You need to recover Group1 and identify the names of the users who were members of Group1 prior to its deletion. You want to achieve this goal by using the minimum amount of administrative effort. What should you do first?
A. Perform an authoritative restore of Group1.
B. Mount the most recent Active Directory backup.
C. Use the Recycle Bin to restore Group1.
D. Reactivate the tombstone of Group1.