Your company has an Active Directory domain that runs Windows Server 2008 R2. The Sales OU   contains an OU for Computers， an OU for Groups， and an OU for Users. You perform nightly backups. An administrator deletes the Groups OU.    You need to restore the Groups OU without affecting users and computers in the Sales OU.    What should you do（）

• A、Perform an authoritative restore of the Sales OU.
• B、Perform an authoritative restore of the Groups OU.
• C、Perform a non-authoritative restore of the Groups OU.
• D、Perform a non-authoritative restore of the Sales OU.