You have an Exchange Server 2010 organization.The organization contains two Mailbox servers named Server1 and Server2.Both servers are members of a database availability group （DAG） named DAG1.Server1 and Server2 have a copy of a mailbox database named DB1.You need to remove the copy of DB1 from Server1.What should you do？（）

• A、From the Exchange Management Shell， run Clean-MailboxDatabase -Identity DB1.
• B、From the Exchange Management Shell， run Remove-MailboxDatabase -Identity DB1/Server1.
• C、From the Exchange Management Console （EMC）， right-click the database copy and select Remove.
• D、From the Exchange Management Console （EMC）， right-click DAG1 and select Manage Database Availability Group Membership.Remove Server1 from the list and click Manage.