You have an Exchange organization. All servers in the organization have Exchange Server
2010 Service Pack 1 (SP1) installed.

The organization contains two Mailbox servers named Server1 and Server2. Each Mailbox
server has one mailbox database and one public folder database.
You discover that all users create public folders on Server1 only.
You need to ensure that all users create public folders on Server2 only.
What should you do?

A.
Move all Mailboxes to Server2

B.
Remove all Public Folder replicas from Server1

C.
Modify the properties of both mailbox databases.

D.
Modify properties of both Public Folder Databases

Explanation:

Public folder referrals have an associated cost number. The numbers range from 1 through
100. This cost number is used to optimize message flow. Specifically, e-mail messages are
routed according to lowest cost number. If two or more routes are available with the same
cost, the load is distributed as equally as possible between them. This cost is also used to
calculate the most appropriate route that the client application (such as Microsoft Outlook)
can use to access public folders on remote servers.

You can also change the default public folder database. This will point the users to the
appropriate public folder database.
Setting a referral cost and default public folder database are both done through the
properties of the mailbox database.

http://technet.microsoft.com/en-us/library/bb629522.aspx
http://technet.microsoft.com/en-us/library/bb629643