Which of the following factors affects the amount of lift produced by a wing?

The factors that affect the amount of lift produced by a wing include wing area, air density, velocity of the aircraft, and angle of attack. These elements come together to determine how effectively a wing can generate lift.

Wing area is crucial because a larger surface area allows for more interaction with the airflow, resulting in increased lift. Air density plays a significant role as well; at higher altitudes, the lower density reduces lift, while greater density at lower altitudes enhances it. The velocity of the aircraft directly influences lift due to the Bernoulli principle, which states that as the speed of the airflow over the wing increases, the pressure decreases, thereby increasing lift. Lastly, the angle of attack is critical; as a wing's angle relative to the oncoming airflow increases, the lift also increases up to a certain point, beyond which stall can occur if the angle becomes too high.

Considering these factors together, option B correctly encapsulates the key elements that determine lift production on a wing.