You have a domain controllernamed Server1that runs Windows Server 2008 R2.
You need to determine the size of the Active Directory database on Server1.
What should you do?

A.
Run the Active Directory Sizer tool.

B.
Run the Active Directory Diagnostics data collector set.

C.
From Windows Explorer, view the properties of the%systemroot%\ntds\ntds.dit file.

D.
From Windows Explorer, view the properties of the%systemroot%\sysvol\domain folder.

Explanation:
http://technet.microsoft.com/en-us/library/cc961761.aspx
Directory Data Store
Active Directory data is stored in the Ntds.ditESE database file. Two copies of Ntds.dit are present in
separate locations on a given domain controller:
%SystemRoot%\NTDS\Ntds.dit This file stores the database that is in use on the domain controller. It
contains the values for the domain and a replica ofthe values for the forest (the Configuration container data).
%SystemRoot%\System32\Ntds.dit This file is the distribution copy of the default directory that is used when
you promote a Windows 2000 – based computer to a domain controller. The availability of this file allows you to
run the Active Directory Installation Wizard (Dcpromo.exe) without your having to use the Windows 2000Server
operating system CD. During the promotion process, Ntds.dit is copied from the %SystemRoot%\System32
directory into the %SystemRoot%\NTDS directory. Active Directory is then started from this new copy ofthe file,
and replication updates the file from other domain controllers.