Question: In a Mission Critical (MC) service scenario, what is the primary purpose of establishing a pre-established session between the MC service client and the MC service server?
Option 1: To facilitate immediate voice communication without additional signaling
Option 2: To exchange necessary media parameters for defining media bearers
Option 3: To authenticate the user for MC service authorization
Option 4: To continuously stream voice in the background for rapid response
Explanation: The correct answer is Option 2 because, as outlined in the context of Mission Critical services, the pre-established session's main goal is to exchange necessary media parameters. This exchange is crucial for defining the media bearers that will be used for communication (e.g., for voice or floor control messages). While immediate voice communication (Option 1) and user authentication (Option 3) are related concepts, they are not the primary purposes of establishing a pre-established session. Continuous voice streaming (Option 4) is also not the main objective, as media bearers can be activated as needed, not necessarily continuously.