Refer to the exhibit.

A customer needs a wireless network upgrade and has these requirements:
✑ Support any applications used on a wired connection
✑ Support up to 2500 wireless clients
✑ Support seamless roaming from floor to floor and building to building
✑ Continue to function seamlessly if one AP or controller fails
The architect has designed the local infrastructure for the network as shown in the exhibit.
Which change should the architect make to better meet customer requirements and best practices?