Which tool should you use?

You need to back up the Contacts lists of all the users in your Lync Server 2010 pool.
Which tool should you use?

A.
Absconfig

B.
Dbimpexp

C.
LDIF Directory Exchange (LDIFDE)

D.
Microsoft Lync 2010

Explanation:
http://www.microsoft.com/learning/en/us/exam.aspx?ID=70-664#tab2

Monitoring and Maintaining Lync Server 2010 (21 percent)
+Back up and restore Lync Server 2010.
+This objective may include but is not limited to: SQL databases and instances, contacts with dbimpexp, topology with Topology Builder, topology with PowerShell and file shares, and activating CMS on a new front end