Question

_______ use split lenses showing red and green colors. the green side faces away from the runway and marks the beginning of usable pavement for arriving aircraft. the red side faces toward the runway and marks the limit of useable pavement for departing aircraft.
options: threshold lights, runway edge lights, taxiway edge lights, runway centerline lights

Explanation:

Threshold lights use split red-green lenses; green faces away (arrival start), red toward runway (departure limit).

Answer:

Threshold lights