Question: What triggers a recalculation of the back-off time in an MBMS (Multimedia Broadcast/Multicast Service) context, potentially requiring a reset of currently running timers?
Option 1: Reception of an updated `associatedDeliveryProcedureDescription` or `sessionDescription` with any changes to timer parameters.
Option 2: Expiration of the existing back-off timer without receiving new data.
Option 3: Detection of network congestion necessitating a slower retry schedule.
Option 4: User Equipment (UE) switching from unicast to multicast mode.
Explanation: According to MBMS protocols, if an updated `associatedDeliveryProcedureDescription` or `sessionDescription` is received with a higher version number, and this update includes changes to the offset-time, random-time-period, or session end time parameters, the back-off time must be recalculated. This ensures adaptability to new transmission settings, potentially requiring a reset of ongoing timers to align with the updated parameters for efficient service delivery.