You need to prevent an Automatic Failover of DAG1 if the WAN Link between the two sites fails but the Servers in both sites are still running

Your Company has a main office and a Disaster Recovery Site.
An Active Directory Site named MainSite exists for the Main Office.
An Active Directory Site named DRSite exists for the Disaster Recovery Site.
The two Sites connect to each other by using a WAN Link. All users work in the Main Office.
You have an Exchange Server 2013 organization.
The organization contains six Servers.
The servers are configured as shown in the following table.

All of the Mailbox Servers are members of a Database Availability Group (DAG) named DAG1.
After a WAN Link failure, you discover that all of the Active Mailbox Database Copies are located
on MBX3, even though MBX1 and MBX2 are still running.
You need to prevent an Automatic Failover of DAG1 if the WAN Link between the two sites fails but the Servers
in both sites are still running.
The solution must prevent two active copies of the same Database.
What should you do?

Answer:

Explanation: