Secondary flight control surfaces include which of the following?

Secondary flight control surfaces are typically used to enhance the effectiveness of primary control surfaces or to make fine adjustments to the aircraft's flight characteristics. Trim tabs are one of these secondary flight control surfaces, as they are designed to help relieve control forces on the primary control surfaces, thereby allowing the pilot to maintain a desired flight attitude without constant pressure on the control yoke or stick.

Trim tabs adjust the aerodynamic characteristics of the primary control surfaces (like ailerons, elevators, and rudders) without requiring direct input from the pilot for every slight adjustment. This reduces pilot workload, enhances stability, and improves comfort during flight.

While wing flaps, ailerons, and slats are all essential components of an aircraft's control system, they are considered primary flight control surfaces or devices that contribute directly to the aircraft's overall aerodynamic efficiency and maneuverability during different phases of flight.