Question: In Mission Critical Video (MCVideo) communications, what characterizes the establishment of an automatic private MCVideo session between two MCVideo clients?
Option 1: A group call alert is sent to all subscribers in a pre-defined group.
Option 2: User interaction is required on both ends to confirm the session setup.
Option 3: One MCVideo client sends a direct request to another, which establishes the session without further user interaction.
Option 4: The MCVideo session is always routed through a central dispatch server for approval.
Explanation: This option correctly describes the automatic commencement of a private MCVideo communication as per the given context. It highlights the direct client-to-client request and the establishment of the session without needing additional user interaction after the initial request, which is key to the 'automatic' aspect of the session commencement in MCVideo communications.