Your network contains an Exchange Server 2010 Service Pack 1 (SP1) organization. The
organization has a single public folder database. You need to prevent all the members of a
group named Sales from accessing the public folders from Outlook Web App.
What should you do first?

A.
From the Exchange Management Console (EMC), modify the Segmentation settings of
the OWA virtual directory.

B.
From the Exchange Management Console (EMC), create a new Outlook Web App
mailbox policy.

C.
From the Exchange Management Shell, run the Set-CasMailbox cmdlet.

D.
From the Exchange Management Shell, run the Add-PublicFolderClientPermission
cmdlet.

Explanation:
http://technet.microsoft.com/en-us/library/dd335191.aspx#EMC