Your network contains two Exchange Server 2010 Service Pack 1 (SP1) Mailbox servers.
You create a database availability group (DAG).
You need to install all of the Failover Clustering components onto the Mailbox servers.
What should you do?

A.
Run the Start-ClusteredMailboxServer cmdlet on both servers.

B.
Run Setup /roles:Mailbox /NewCMS on both servers.

C.
Add both servers to the DAG.

D.
Install the Application server role on both servers.

Explanation:

http://technet.microsoft.com/en-us/library/dd298065.aspx