Question: What is a possible reason for the network to initiate GMM common procedures in a mobile radio interface?
Option 1: To establish a new bearer context.
Option 2: To release an existing bearer context.
Option 3: To modify the QoS parameters of an existing bearer context.
Option 4: To authenticate and cipher the communication between the UE and the network.
Explanation: The network may initiate GMM common procedures, such as authentication and ciphering, to ensure secure communication between the User Equipment (UE) and the network. This is a critical aspect of mobile radio interface protocols, as it protects user data and prevents unauthorized access to the network.