Your network contains an Active Directory domain. All domain controllers run Windows
Server 2008 R2.
You need to compact the Active Directory database.
What should you do?

A.
Run the Get-ADForest cmdlet.

B.
Configure subscriptions from Event Viewer.

C.
Run the eventcreate.exe command.

D.
Configure the Active Directory Diagnostics Data Collector Set (OCS).

E.
Create a Data Collector Set (DCS).

F.
Run the repadmin.exe command.

G.
Run the ntdsutil.exe command.

H.
Run the dsquery.exe command.

I.
Run the dsamain.exe command.

J.
Create custom views from Event Viewer.

Explanation:
Reference 1)
http://technet.microsoft.com/en-us/library/cc794920.aspx
Compact the Directory Database File (Offline Defragmentation)
You can use this procedure to compact the Active Directory database offline. Offline
defragmentation returns free disk space in the Active Directory database to the file system.

As part of the offline defragmentation procedure, check directory database integrity.
Performing offline defragmentation creates a new, compacted version of the database file in
a different location.
Reference 2)
Mastering Windows Server 2008 R2 (Sybex, 2010) page 805
Performing Offline Defragmentation of Ntds.dit
These steps assume that you will be compacting the Ntds.dit file to a local folder. If you plan
to defragment and compact the database to a remote shared folder, map a drive letter to that
shared folder before you begin these steps, and use that drive letter in the path where
appropriate.
1. Open an elevated command prompt. Click Start, and then right-click Command Prompt.
Click Run as Administrator.
2. Type ntdsutil, and then press Enter.
3. Type Activate instance NTDS, and press Enter.
4. At the resulting ntdsutil prompt, type Files (case sensitive), and then press Enter.
5. At the file maintenance prompt, type compact to followed by the path to the destination
folder for the defragmentation, and then press Enter.