Question: What is the purpose of steps 5 and 6 in the RRC inactive to other RRC states transition procedure, as described in the context?
Option 1: To send Paging message to UE.
Option 2: To allocate gNB-CU UE F1AP ID and setup UE context for inactive to active transitions.
Option 3: To generate RRCResume/RRCSetup/RRCReject/RRCRelease message towards the UE.
Option 4: To forward RRC message to the UE over SRB0 or SRB1.
Explanation: Steps 5 and 6 in the RRC inactive to other RRC states transition procedure are used for UE Inactive to UE Active transitions, excluding transitions due to signalling exchange only. The gNB-CU allocates gNB-CU UE F1AP ID and sends UE CONTEXT SETUP REQUEST message to gNB-DU, which may include SRB ID(s) and DRB ID(s) to be setup. This is necessary for setting up the UE context for inactive to active transitions.