Your network has Lync Server 2010 deployed. You plan to deploy two Edge Servers. You need to recommend a solution to ensure that remote users can sign in to their Lync account if a single server fails.
What should you include in the recommendation?

A.
a Network Load Balancing (NLB) cluster

B.
a hardware load balancer

C.
a Director pool

D.
a reverse proxy server

Explanation:
NLB is also a viable option, as Lync Edge role supports it, but as a rule of thumb HLB is better. (http://technet.microsoft.com/en-us/library/gg398634.aspx)