Question: In a 5G network, when a Vertical Application Server (VAL) decides to release an MBS (Multicast/Broadcast Service) session due to inactivity of the associated VAL service group, what is the next step taken by the VAL server to initiate the release of network resources?
Option 1: The VAL server sends an MBS session deletion request directly to the MB-SMF (Multicast-Broadcast Session Management Function), providing the corresponding MBS session ID.
Option 2: The VAL server invokes the multicast/broadcast resource release service of the Network Resource Manager (NRM) server, which then triggers the NRM server to send an MBS session deletion request to the 5GS.
Option 3: The VAL server notifies the User Equipment (UE) to stop monitoring the broadcast MBS session or leave the multicast MBS session without involving any other network entity.
Option 4: The VAL server updates its internal database to reflect the inactivity of the VAL service group and waits for a periodic cleanup process to release the MBS session.
Explanation: The question seeks the immediate action following the VAL server's decision. However, based on the provided context, it's crucial to understand that in practical telecom scenarios, the VAL server's decision to release resources typically involves notifying or interacting with network management entities before direct requests to session management functions like MB-SMF.