Your company has a data center. The data center contains a server that has Exchange Server 2016 and the Mailbox server role installed. Outlook Anywhere clients connect to the
Mailbox server by using the name outlook.contoso.com.
The company plans to open a second data center and to provision a database availability group (DAG) that spans both data centers.
You need to ensure that Outlook Anywhere clients can connect if one of
the data centers becomes unavailable.
What should you add to DNS?
A. one A record
B. two TXT records
C. two SRV records
D. one MX record
References:
https://technet.microsoft.com/en-gb/library/dd638104(v=exchg.150).aspx?f=255&MSPPError=-2147
217396