You have an Exchange Server 2010 Service Pack 1 (SP1) organization. All users access their mailbox by using Microsoft Outlook 2010. You plan to implement two Client Access servers. You need to design a Client Access server solution that meets the following requirements:
Ensures that all of the users can access their mailbox if a Client Access server fails. Ensure that all of the users can access their mailbox if a Client Access server service fails.

What should you include in the design? (Choose all that apply.)

A.
a Client Access array

B.
a hardware based load balancer

C.
a Network Load Balancing cluster

D.
an SMTP relay

E.
DNS round robin

F.
multiple MX records