You need to compact an Active Directory database on a domain controller that runs Windows Server 2008 R2

You need to compact an Active Directory database on a domain controller that runs Windows Server 2008 R2. What should you do?

A.
Run defrag.exe /a /c.

B.
Run defrag.exe /c /u.

C.
From Ntdsutil, use the Files option.

D.
From Ntdsutil, use the Metadata cleanup option.