Which of the following is considered an auxiliary flight control?

Leading-edge flaps are considered an auxiliary flight control because they enhance the aerodynamic efficiency and control of an aircraft, particularly during the critical phases of flight such as takeoff and landing. By altering the shape of the wing, leading-edge flaps help increase lift at lower speeds, allowing the aircraft to maintain stability and control. This is especially important for aircraft that operate at a wide range of speeds and configurations. While the primary flight controls like the ailerons, elevators, and rudder manage the basic movement and attitude of the aircraft, auxiliary controls such as leading-edge flaps provide additional aerodynamic benefits that supplement the primary systems.