Which relationship is correct when comparing drag and airspeed?

The correct relationship concerning drag and airspeed involves induced drag, which is the drag that results from lift generation. Induced drag is directly affected by the airspeed of the aircraft. As the airspeed increases, the induced drag decreases. This relationship occurs because increased airspeed leads to a reduction in the angle of attack required to maintain lift. Hence, induced drag varies inversely with the square of the airspeed, meaning that as the speed doubles, the induced drag actually decreases to one-fourth.

Understanding this inverse relationship is crucial for pilots and instructors as it emphasizes the importance of maintaining optimal airspeeds to manage drag effectively during flight. The other options incorrectly represent the relationship between drag types and airspeed, leading to misunderstandings of aerodynamic principles.