What should you recommend?

You have an Exchange Server 2013 organization. The organization contains four servers in the same
Active Directory site. The servers are configured as shown in the following table.

EXB and EX4 are members of a database availability group (DAG) named DAG1. All users use
Microsoft Outlook 2013 to connect to their mailbox.
You need to recommend a client access solution to ensure that all of the users can connect to their
mailbox if EX1 or EX2 fails.
What should you recommend?

A.
Add a layer 4 hardware load balancer that balances RPC traffic

B.
Add a layer 7 hardware load balancer that balances the traffic on port 443.

C.
Add a layer 7 hardware load balancer that balances RPC traffic.

D.
Replicate all of the databases in DAG1 to both DAG1 members.