Question: When a mobile IAB-node's authorization status changes to 'not authorized' and it connects to a different IAB-donor-CU for RRC termination and F1 interface termination, what action does the F1-terminating IAB-donor-CU take after receiving the updated authorization status?
Option 1: Immediately releases all backhaul resources for the mobile IAB-node without attempting to hand over served UEs.
Option 2: Requests additional authorization from the 5GC before taking any action.
Option 3: Attempts to establish new backhaul resources with a different BAP address and TNL address.
Option 4: Attempts to hand over the UEs served by the mobile IAB-node to other cell(s), and then releases the F1 interface towards the mobile IAB-DU.
Explanation: This is the correct sequence of actions for handling a change in authorization status to 'not authorized' when connecting to different IAB-donor-CUs. The F1-terminating IAB-donor-CU first tries to ensure continuity of service for the UEs by handing them over, then releases resources directly associated with the mobile IAB-DU's F1 interface.