You have three nps servers known as server1, server2, and server3. on server1, you have a remote radius server group that contains server2 and server3. server2 and server 3 are configured to authentication remote users. what do you need to do to configure server1 to forward radius authentication requests to server2 and server3?

In order server1 to forward radius authentication requests to server2 and server3 network policy should be created. Creating a network policy means setting the rules, conditions and constraints that determine who is authorized to connect to the network and who is not. So, putting Server  in the list will enable him to forward radius requests to server 2 and 3. 

Ithink the answer is a.