You need to ensure that the hardware load balancer distributes traffic evenly across both Client Access servers

You have an Exchange Server 2013 organization that contains one Client Access server. The Client
Access server is accessible from the Internet by using a network address translation (NAT) device.
You deploy an additional Client Access server. You also deploy an L4 hardware load balancer
between the Client Access servers and the NAT device. After deploying the hardware load balancer,
you discover that all of the Exchange Server traffic is directed to a single Client Access server. You
need to ensure that the hardware load balancer distributes traffic evenly across both Client Access
servers. What should you do?

A.
Change the default route of the Client Access servers to point to the hardware load balancer.

B.
Configure the NAT device to pass the original source IP address of all connections from the
Internet.

C.
Configure the Client Access servers to have a second IP address and web site. Create the Exchange
virtual directories in the new sites.

D.
Configure SSL offloading on the hardware load balancer and the Client Access servers.

Explanation:
Level 4 Load Balancer
A load balancer is a server computer with a very specialized operating system tuned to manage
network traffic using user-created rules. Enterprises and hosting companies rely on load-balancing
devices to distribute traffic to create highly available services L4 load balancing is fairly simple, two
servers sharing the same IP address. You get redirected to the less-busy server.
The most popular Layer 4 load balancing techniques are:
round-robin
weighted round-robin
least connections
weighted least connections
NOT A
http://pdfs.loadbalancer.org/Microsoft_Exchange_2013_Deployment_Guide.pdf
If there was no NAT device and the load balancer was completing the NAT translation then there
maybe some merit in this answer option. B is a better answer given this scenario.
NOT C
No need to configure the Client Access servers to have a second IP address.
NOT D
Not required in this scenario
SSL offloading relieves a Web server of the processing burden of encrypting and/or decrypting traffic
sent via SSL, the security protocol that is implemented in every Web browser.
The processing is offloaded to a separate device designed specifically to perform SSL acceleration or
SSL termination.
B) When using source NAT, the client IP address is not passed to the load balanced server. The insertion
of the Client IP address into the header allows the exchange servers to see the IP that made the
connection.
http://pdfs.loadbalancer.org/Microsoft_Exchange_2013_Deployment_Guide.pdf