How does adverse yaw occur with aileron input?

Adverse yaw occurs as a result of aileron input due to the unequal distribution of lift and drag among the wings. When a pilot uses the ailerons to initiate a roll, one aileron moves down while the opposite one moves up. The aileron that moves down increases the camber of that wing, generating more lift but also more induced drag. In contrast, the aileron that moves up decreases the camber of its wing, resulting in less lift and less drag.

As a consequence, the wing with the increased lift (and drag) will experience a yawing motion towards that side. This phenomenon of the aircraft yaws in the opposite direction of the intended roll is what characterizes adverse yaw. Thus, the correct answer reflects the dynamics of lift and drag being altered by the movement of the ailerons, leading to an unintended yaw during a roll maneuver. Understanding this principle is crucial for pilots when executing maneuvers, especially when coordinating aileron and rudder inputs to counteract adverse yaw.