You have an Exchange organization. All servers in the organization have Exchange Server
2010 Service Pack 1 (SP1) installed.
The organization contains a database availability group (DAG) named DAG1. DAG1
contains three Mailbox servers including a server named Server1.
Server1 fails.
You restore Server1.
You need to ensure that Server1 can replicate mailbox databases from DAG1.
What should you do first?

A.
Modify the GUID for Server 1

B.
Removed the object for Server1 from DAG1.

C.
Remove the default Mailbox Database from Server 1

D.
Disable log truncation for the Mailbox database in DAG1

Explanation:
Should be C:
Remove-DatabaseAvailabilityGroupServer -Identity DAG1 -MailboxServer MBX1
http://technet.microsoft.com/en-us/library/dd638206.aspx