Question: In a Mission Critical (MC) service scenario, what triggers the MC Gateway UE to send a notification to the corresponding MC Gateway Client hosted on a non-3GPP device?
Option 1: Periodic Heartbeat Signal Loss
Option 2: Change or Adjustment in Connection Circumstances
Option 3: Successful Re-establishment of a New Connection
Option 4: Receipt of an MC Service Termination Message from the Network
Explanation: The correct answer, "Change or Adjustment in Connection Circumstances", aligns with the described mechanism where the connection with the corresponding MC Gateway UE needs to be adjusted due to various reasons (as detailed in Annex D, though not referenced here as per guidelines). This scenario necessitates the MC Gateway UE to notify the client, ensuring seamless adaptation to new conditions. The other options do not directly relate to the circumstance under which the UE would initiate such a notification for the purpose of adjusting or changing the connection.