Refer to the exhibit. Which option prevents the AP from completing the DTLS join process?

The Self-Signed Certificate (SSC) on the Access Point (AP) must be authorized by the Wireless LAN Controller (WLC) for the DTLS join process to successfully establish a secure connection. If the SSC is unauthorized, the WLC will reject the AP's connection attempt, preventing it from joining.

A missing root CA on the WLC would primarily affect the WLC's ability to validate other certificates, not typically cause an AP's SSC to be unauthorized for joining.

While an incorrect date on the WLC can cause certificate validation failures due to validity periods, the specific issue of an unauthorized SSC points to a direct trust or provisioning problem.

An intermediary CA missing on the WLC would prevent validation of a certificate chain, but the problem statement points to the AP's SSC itself being unauthorized, rather than a chain validation issue.