Your company has three data centers. The data centers are located in Montreal, New York, and Seattle.
You have an Exchange Server 2013 organization that contains six servers. The servers are configured as shown in the following table.

The organization is configured as shown in the following exhibit. (Click the Exhibit button.)

The file share witness for DAG1 is located on EX3.
You plan to implement site resiliency and use a single name space named mail.contoso.com.
You need to recommend a solution to minimize the amount of time that the Exchange Server services are unavailable if either the data center in Montreal or the data center in Seattle fails.
Which two tasks should you recommend performing? (Each correct answer presents part of solution.
Choose two.)
Correct Answer: A,D
Explanation/Reference:
Explanation:
When a DAG has been deployed across two datacenters, a new configuration option in Exchange 2013 is to use a third location for hosting the witness server. If your organization has a third location with a network infrastructure that is isolated from network failures that affect the two datacenters in which your DAG is deployed, then you can deploy the DAG's witness server in that third location, thereby configuring your DAG with the ability automatically failover databases to the other datacenter in response to a datacenter- level failure event.
By creating two DNS host (A) records for mail.contoso.com, we can use DNS Round Robin to distribute connections between the two CAS servers. If one server goes down, a client will attempt to connect to the CAS server specified in the second DNS record.