What component is used to adjust light output from instruments and displays in the cockpit?

The trim control panel serves as the correct answer because it includes features specifically designed for managing the cockpit's lighting conditions. By allowing pilots to adjust the brightness of instruments and displays, it ensures that they can maintain optimal visibility and readability under various lighting conditions, which is crucial for safety and situational awareness during flight.

The other components mentioned do not function to regulate light output. The control stick primarily aids in maneuvering the aircraft, the instrument panel displays critical flight data but does not provide lighting adjustments, and the flight control panel focuses on aircraft control settings rather than cockpit lighting. Thus, the trim control panel is specifically designed for the critical task of adjusting and managing illumination in the cockpit.