What is the principle behind an airfoil generating lift?

The principle behind an airfoil generating lift is based on the creation of a pressure difference above and below the wing. As an aircraft moves through the air, the shape of the airfoil, which is typically curved on the top and flatter on the bottom, causes the air to travel faster over the top surface than the bottom surface. According to Bernoulli’s principle, as the speed of the airflow increases, the pressure decreases. Consequently, the reduced pressure on top of the wing and the higher pressure below it creates an upward lift force, allowing the aircraft to fly.

The other options do not accurately describe the primary mechanism for lift generation. Reduced speed of airflow would not create sufficient lift; rather, it could cause a loss in lift. Increasing the wing surface area can contribute to increased lift, but it is not the fundamental principle by which lift is generated. Sound wave interaction is unrelated to the aerodynamic principles that govern lift generation in the context of airfoils.