Which control device is responsible for pitch control about the lateral axis?

The elevator or stabilator is the control device that is primarily responsible for pitch control about the lateral axis of an aircraft. The lateral axis runs from wingtip to wingtip, and controlling pitch means adjusting the angle of the aircraft's nose relative to the horizon. When the elevator is deflected upward, it causes the tail of the aircraft to move down, resulting in a nose-up attitude, which increases the aircraft's pitch. Conversely, when the elevator is deflected downward, the tail rises, and the nose drops, decreasing the pitch.

This mechanism allows the pilot to manage ascent and descent during flight. While other control devices like the rudder and ailerons play essential roles, they govern directional control and roll, respectively, rather than pitch. The throttle affects the engine power and speed but does not directly influence the aircraft's pitch. Thus, the elevator/stabilator is the correct choice for controlling pitch around the lateral axis.