Question: What happens when an IAB-node orderly release is initiated and both the F1 interface and IAB-MT need to be released?
Option 1: The IAB-donor-CU releases the collocated IAB-MT before removing the F1 interface connection to the IAB-DU.
Option 2: The IAB-donor-CU removes the F1 interface connection to the IAB-DU and then performs the deregistration procedure for the IAB-MT.
Option 3: The IAB-donor-CU releases the BH RLC channels in the intermediate hops before removing the F1 interface connection to the IAB-DU.
Option 4: The IAB-donor-CU removes the F1 interface connection to the IAB-DU before releasing the collocated IAB-MT.
Explanation: According to the orderly release procedure, if both the F1 interface and IAB-MT need to be released, the IAB-donor-CU should remove the F1 interface connection to the IAB-DU before it releases the collocated IAB-MT. This ensures that the F1 interface is properly disconnected before releasing the IAB-MT.