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 on to the Mailbox servers. What should you do？（）

• A、Add both servers to the DAG
• B、Install the Application server role on both servers
• C、Run Setup /roles：Mailbox /NewCIMS on both servers
• D、Run the Start-ClusteredMailboxServer cmdlet on both servers