Define 'Air Traffic Control System'.

The term 'Air Traffic Control System' encompasses the comprehensive framework that maintains safe and efficient aircraft movement within controlled airspace. This includes not only the technological tools and systems utilized for tracking and communicating with aircraft but also the trained personnel responsible for managing air traffic and the standardized procedures that guide their actions.

By defining the Air Traffic Control System in this way, it highlights the importance of coordination between human operators and technology to ensure that aircraft can safely navigate congested airspaces. This system involves radar, radio communication, flight planning, and real-time data processing to monitor the positions and trajectories of multiple aircraft simultaneously, minimizing the risk of collisions.

While some options mention aspects relevant to air traffic control—like communication channels between pilots and ground control, regulations for pilots during flights, and maintenance technology—they do not fully encapsulate the complete system that includes all operational elements working together to achieve safe air traffic management. Thus, the chosen answer accurately represents the holistic nature of the Air Traffic Control System.