Which of the following represents the four forces acting on an aircraft in flight?

The four fundamental forces acting on an aircraft during flight are lift, weight (gravity), thrust, and drag.

Lift is the upward force generated by the wings as air flows over them, opposing the weight of the aircraft. Weight refers to the gravitational pull acting downward toward the Earth, and it is a critical factor that must be overcome for the aircraft to become airborne. Thrust is the forward force produced by the engines, propelling the aircraft through the air, while drag is the resistance encountered as the aircraft moves through that air.

Option C correctly identifies these four essential forces, illustrating the balance required for an aircraft to achieve and maintain flight. Understanding how these forces interact is crucial for pilots and those studying aviation, as they must ensure that thrust exceeds drag for acceleration and lift exceeds weight for ascension.