Correct option is D
For night landing, the runway threshold lights are colored green to indicate the start of the usable portion of the runway for landing aircraft. The green lights are positioned at the beginning of the runway and are visible to approaching aircraft, ensuring safe alignment during landing.
Detailed Explanation of Options:
1. Yellow:
Used for cautionary signals and edge markings, not for runway thresholds.
2. White:
Used for runway edge lights and centerline lights, but not for thresholds.
3. Red:
Used to indicate the runway end (stop end lights), not the threshold.
4. Green:
Correct, as green lights mark the runway threshold and signal the beginning of the landing area.
