In ATC, what information do threshold lights provide to pilots?

Threshold lights are specifically designed to indicate the position of the landing threshold of a runway to pilots. These lights are usually located at the beginning of the runway and help in visually defining where the runway starts. This is critical for pilots during the approach phase of landing, particularly in low visibility situations or at night, as they help ensure that the aircraft aligns correctly with the landing runway. The visibility of these lights informs pilots that they are in the correct position to safely land and continue with their landing procedure.

In contrast, the other options provided do not accurately relate to the purpose of threshold lights. The location of the control tower is typically indicated through different signage and lighting. Clearance for takeoff is managed through air traffic control communications, and information about runway closures is disseminated through NOTAMs (Notices to Airmen) and other communications, not through threshold lighting. Thus, the role of threshold lights is solely focused on defining the landing threshold.