Which of the following is considered a primary flight control?

The elevator is considered a primary flight control because it directly influences the pitch of the aircraft, allowing it to ascend or descend. The elevator is an integral part of the tail section of the aircraft and works by changing the airflow over the tail, thus altering the aircraft's angle of attack. This control is crucial during various phases of flight, such as climbing, cruising, and descending, as it enables the pilot to maintain the desired flight path and attitude.

In contrast, the other options do not serve the same primary role in actively controlling the aircraft's attitude. The dorsal fin provides stability and helps with directional control but is not directly responsible for pitch. Slats are high lift devices that enhance the wing’s performance during takeoff and landing but do not control the aircraft’s pitch. The wing tip, while it contributes to the overall aerodynamic efficiency of the wing and can influence roll stability, does not directly control flight attitudes like the elevator. Understanding the primary flight controls, like the elevator, is essential for safe and effective aircraft operation.