What type of lights are constantly illuminated at the trailing edge of each wingtip?

The correct choice relates to the standard lighting regulations governing aircraft. The lights at the trailing edge of each wingtip are designed to enhance visibility and situational awareness for both the pilots and other aircraft in proximity.

Specifically, white position lights are mounted on the wingtips and are illuminated constantly during flight. These white lights serve an important function in indicating the aircraft's position and orientation to others, particularly in low-light conditions or at night.

The other types of position lights—red and green—are also used on aircraft but are specifically located at the front: the left wingtip features a red light, and the right wingtip has a green light. Blue position lights are not standard on most commercial aircraft and may be found in specific aircraft types or configurations.

Thus, identifying the wingtip lights as white reinforces understanding of aviation lighting systems and their purposes within air traffic management and safety protocols.