Which change to the existing infrastructure should the architect recommend to support all of the customer requirements?

Refer to the exhibit.

A customer has a wired infrastructure shown in the exhibit. The customer is in the process of expanding their wireless services. They will now add a new wireless solution, with mobility controllers (MCs) connected as shown. The new wireless solution will support a total of 450 APs and about 26,000 wireless devices. It must provide seamless roaming across the entire campus.

After the new deployment, both wired and wireless devices experience IP connectivity issues.

Which change to the existing infrastructure should the architect recommend to support all of the customer requirements?
A . The MCs should be moved to the aggregation layer, and more MCs added.
B . The core and aggregation switches should disable Virtual Switching Framework (VSF).
C . The core switches should be replaced with switches that have larger ARP tables.
D . The wired VLANs should be combined into a single VLAN and /16 subnet.

Answer: B