What visual illusion is caused by tall wavy grass that makes the pilot continuously adjust flight controls?

The visual illusion caused by tall wavy grass that leads a pilot to continuously adjust flight controls is best represented by induced motion. This phenomenon occurs when a fixed object, like grass, is seen moving due to the motion of the viewer or the frame of reference nearby. In this case, when the pilot sees the grass moving in the wind or swaying, it can give the false impression that the aircraft is also moving or tilting, leading to unnecessary control adjustments.

Induced motion can create a disconnect between what the pilot perceives and the actual position and orientation of the aircraft, increasing the likelihood of misperceptions regarding altitude and attitude. This confusion may result in overcorrection, which can ultimately affect the safety of flight in low-level flying situations.

In contrast, the other options describe different visual phenomena that do not specifically relate to the situation of controlling an aircraft in response to the sight of moving grass. For example, size-distance illusion pertains to how the size of an object can mislead the viewer about its distance, ground illusion involves misperceptions related to the runway or landing environment that could affect altitude perception, and motion parallax describes how objects at varying distances appear to move at different speeds as you change your viewpoint, which isn't directly