Which of the following is classified as an auxiliary flight control?

Leading-edge flaps are classified as auxiliary flight controls because they provide additional lift and improve the aircraft's aerodynamics during critical phases of flight, such as takeoff and landing. These flaps are often used to enhance the stall characteristics of the wing and can be deployed in conjunction with other primary flight controls. While primary flight controls like ailerons, elevators, and rudders directly influence the aircraft’s attitude and flight path, auxiliary controls like leading-edge flaps contribute to overall performance and safety, particularly at lower speeds. By improving the airflow over the wing and increasing lift, leading-edge flaps help reduce the stall speed and enable better handling qualities, thus playing a crucial role in maintaining safe operability during specific flight conditions.