Refer to the exhibit. Which statement about the join process of the access point is true?

Certificate validity problems arise during the secure tunnel establishment phase, after discovery requests have been successfully received and processed.

The rejection of all discovery requests directly contradicts a successful AP join to the controller.

If the AP had moved to its primary controller, it would not be sending discovery requests to this controller for rejection.

MAC address issues would typically result in authentication failures or database mismatches after discovery, not in the initial non-reception of discovery requests.

If the controller rejects all discovery requests because they are 'not received on the' expected interface or UDP port, it points to a fundamental network issue. This means the AP's initial attempts to find a controller are failing at a very basic layer, such as incorrect routing, firewall blocking, or misconfigured controller listening ports, preventing any further join steps.