Which statement about the join process of the access point is true?
Refer to the exhibit.
A. The time on the controller is outside of the certificates validity time interval, so the join phase failed.
B. The AP successfully joined the controller.
C. The AP moved from this controller to its primary controller.
D. The AP failed to join because the MAC address of the AP was not correct on the controller.
E. The controller rejected all discovery requests from the AP because they were not received on the management interface subnet.
D
The reason for error that occured last is “radius authorization of the ap has failed”.
From the link below –
“On the logs “: Radius authorization of the AP has failed ” means that this needs the MAC address to be in the mac filter or ap policies.”
https://community.cisco.com/t5/other-wireless-mobility-subjects/1552e-not-joining-4400-wlc/td-p/2544825
E is good answer : unsupported VLAN = reject all discovery request form AP