Your company has offices in New York and Miami. The offices connect to each other by using a dedicated WAN link. Each office has a direct connection to the Internet. An Active Directory site exists for each office. Each office contains one Mailbox server, two Hub Transport servers, and two Client Access servers. All servers have Exchange Server 2010 Service Pack 1 (SP1) installed and run Windows Server 2008 R2. The Mailbox servers are configured as shown in the following table.

Mailbox server name Mailbox database name Number of mailboxes Office location
MBX-01                            MDB-01                                 300                                                  New York
MBX-02                            MDB-02                                 1,000                                             Miami

You need to recommend a high-availability solution for the Mailbox servers that meets the following requirements:

* The mailbox databases must be automatically available if a single Mailbox server fails.
* The mailbox databases must be automatically available if the WAN link between the offices fails.
* The mailbox databases must be available if all of the Exchange servers in an office become unavailable, after an administrator performs a manual failover.

Which of the following solutions is the best recommendation? (More than one answer choice may achieve the goal. Select the BEST answer.)

A.
Add a Mailbox server to each office.
Create one database availability group (DAG).
Add all Mailbox servers to the DAG.
Add a file share witness to the Miami office.
Create a copy of each mailbox database.

B.
Add a Mailbox server to each office.
Create two database availability groups (DAGs).
Add one Mailbox server from each office to each DAG.
Add a file share witness to each office.
Create a copy of each mailbox database.

C.
Add two Mailbox servers to each office.
Create one database availability group (DAG).
Add all of the Mailbox servers in the Miami office to the DAG.
Add a file share witness to the New York office.
Create a copy of each mailbox database.
Add two Mailbox servers to the Miami office.

D.
Add one Mailbox server to the New York office.
Create two database availability groups (DAGs).
Add all of the Mailbox servers in the Miami office to one of the DAGs.
Add all of the Mailbox servers in the New York office to the other DAG.
Add a file share witness to each office.
Create a copy of each mailbox database.