A corporate environment includes Exchange Server 2010 SP1 deployed in a primary datacenter and in a secondary datacenter. The datacenters are in separate Active Directory Domain Services (AD DS) sites. Each datacenter includes AD DS domain controllers, Global Catalog servers, DNS servers, and two Mailbox servers. The primary datacenter contains one file share witness. All Mailbox servers are members of one database availability group (DAG). Each datacenter has independent Internet access. A dedicated high-speed network connection exists between the datacenters. You are designing a failover plan. You have the following requirements:
* Provide a highly available solution in the event that the primary datacenter fails. Provide mailbox access for employees through the secondary datacenter.
* Ensure that each Mailbox database is active in only one location at a time.
* Ensure that failback to the primary datacenter completes gracefully.
You need to design a solution that meets the requirements.
What should you recommend?
A.
Enable datacenter activation coordination (DAC) mode before an outage occurs. During an outage, stop and disable any running Exchange services in the primary datacenter, validate the health of the secondary datacenter Exchange servers, and activate the secondary datacenter Mailbox servers.
B.
Disable datacenter activation coordination (DAC) mode before an outage occurs. During an outage, ensure that all Exchange services in the primary datacenter are running, validate the health of the secondary datacenter Exchange servers, and activate the secondary datacenter Mailbox servers.
C.
Configure the AutoDatabaseMountDial property to BestAvailability on all Mailbox servers before an outage occurs. During an outage, stop and disable any running Exchange services in the primary datacenter, validate the health of the secondary datacenter Exchange servers, and restart the secondary datacenter Mailbox servers.
D.
Configure the AutoDatabaseMountDial property to Lossless on all Mailbox servers before an outage occurs. During an outage, ensure that all Exchange services in the primary datacenter are running, validate the health of the secondary datacenter Exchange servers, and restart the secondary datacenter Mailbox servers.