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), create a new Outlook Web App mailbox policy.

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

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

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

Explanation:
Reference:

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