Concept:Friction due to air mass is called air resistance or drag. It is reduced by giving objects a streamlined shape.Explanation:When an object moves through air, the air exerts a resistive force on it.A streamlined shape allows air to flow smoothly around the object, reducing turbulence and drag.Streamlining is commonly used in aeroplanes, cars, and boats to reduce air friction.The correct option that describes this method is "streaming", meaning a streamlined shape.Answer:A. streaming