Which controller option allows a user to switch from the provisioning SSID to the employee SSID after registration?

User Idle Timeout disconnects inactive users after a period and does not facilitate a smooth transition between SSIDs after registration.

AAA Override allows the authentication server to dynamically push policy attributes to a WLC, but it does not directly control the client's ability to switch SSIDs.

Fast SSID Change is a feature on wireless LAN controllers that enables clients to seamlessly transition between SSIDs without going through a full re-association process. This is particularly useful in scenarios where a client connects to a provisioning SSID for onboarding and then needs to move to an employee SSID upon successful registration or authentication, providing a smoother user experience.

AP SSID Fallback is a mechanism for an AP to broadcast a secondary SSID, which is unrelated to a client switching SSIDs after registration.