What is parasite drag?

Parasite drag refers to the drag that is incurred by an aircraft as it moves through the air due to friction and pressure differences created by its shape and surface characteristics. This type of drag encompasses factors such as the shape of the aircraft and the surface roughness, which contribute to the resistance experienced as air flows over the aircraft’s surfaces.

When considering the choices, the correct option identifies this friction component, which is not tied to the generation of lift, the weight of the aircraft, or specific maneuvers like bank turns. Lift generation relates to induced drag rather than parasite drag, while an aircraft's weight is not a direct cause of drag but rather affects the overall force balance during flight. Bank turns can influence drag, but they do not represent the definition or mechanism of parasite drag itself. Thus, the answer highlights the specific nature of parasite drag as being primarily attributable to air friction over the aircraft's structure.