Refer to the exhibit.

A network architect is designing the logical topology for a campus LAN networking solution. The customer requires support for 2400 edge ports, which is provided by 10 intelligent Resilient Framework (IRF) groups at the access layer. This customer does not have a wireless network nor anticipants adding one in the next two years. However, the customer does want to authenticate users with 802.1X and use the network RADIUS server to divide users from different groups into different VLANs. The customer has three user groups, each of which includes between 600 and 900 users.
Additionally, the customer understands that the RADIUS server will require several policies but wants to keep these policies as simple and easy to maintain as possible.
How can the network architect ensure that the solution meets the customer needs and also follows best practice?