Final answer:
Weather Monitoring System is not a basic element of STARS, which mainly consists of radar, flight data processing, and a voice communication system.
Step-by-step explanation:
The item that is not a basic element of the Standard Terminal Automation Replacement System (STARS) is option 4) Weather Monitoring System. STARS integrates several key functions for air traffic control, including radar, which is used for detecting and tracking the position of aircraft based on microwave echoes, flight data processing, which manages flight plans and other related data, and a voice communication system, which allows controllers to communicate with pilots. Weather monitoring, while critical to air traffic management, is usually handled by separate systems that are integrated into the broader air traffic control system rather than being a basic element of STARS itself.