Your company has four offices.
The offices are located in Montreal, Seattle, New York, and Miami.
Users access all of the web-based resources by using web proxy servers.
The IP addresses of the web proxies at each office are configured as shown in the following table.
The connections to the web proxies are balanced by using round-robin DNS.
The company plans to deploy a new application.
The new application has a farm of front-end web servers that connect to a back-end application server.
When a session to a web server is established, the web server stores data until the session closes.
Once the session closes, the data is sent to the application server.
You need to ensure that the incoming sessions to the web server farm are distributed among the web servers.
The solution must ensure that if a web server fails, the users are NOT directed to the failed server.
How should you configure the port rule? To answer, select the appropriate options in the answer area.
Hot Area:
Answer: 
Correct: https://technet.microsoft.com/en-us/library/cc771709(v=ws.11).aspx
I realize the link is for 2008R2, but NLB affinity has not changed.
It is “Network” due to the proxy server aspect of the question.
For Filtering mode, configure the following parameters:
The Multiple hosts parameter specifies that multiple hosts in the cluster will handle network traffic for the associated port rule. This filtering mode provides scaled performance and fault tolerance by distributing the network load among multiple hosts. You can specify that the load be equally distributed among the hosts or that each host will handle a specified load weight.
The Single host parameter specifies that network traffic for the associated port rule be handled by a single host in the cluster according to the specified handling priority. This filtering mode provides port specific fault tolerance for handling network traffic.
The Disable this port range parameter specifies that all network traffic for the associated port rule be blocked. In this case, the NLB driver filters all corresponding network packets or datagrams. This filtering mode lets you block network traffic that is addressed to a specific range of ports.
The Affinity parameter is applicable only for the Multiple hosts filtering mode.
The None option specifies that multiple connections from the same client IP address can be handled by different cluster hosts (there is no client affinity). To allow Network Load Balancing to properly handle IP fragments, you should avoid using None when selecting UDP or Both for your protocol setting.
The Single option specifies that NLB should direct multiple requests from the same client IP address to the same cluster host. This is the default setting for affinity. You can optionally modify the NLB client affinity to direct all client requests from a TCP/IP Class C address range (instead of a single IP address) to a single cluster host by enabling the Network option instead of the Single option. This feature ensures that clients that use multiple proxy servers to access the cluster can have their TCP connections directed to the same cluster host.
The Network option specifies that NLB direct multiple requests from the same TCP/IP Class C address range to the same cluster host. Enabling Network affinity instead of Single affinity ensures that clients that use multiple proxy servers to access the cluster have their TCP connections directed to the same cluster host.
The use of multiple proxy servers at the client’s site causes requests from a single client to appear to originate from different computers. Assuming that all of the client’s proxy servers are located within the same address range, Network affinity ensures that client sessions are properly handled. If you do not need this capability, use Single affinity to maximize scaled performance.