The four subtasks of riding include social, emotional, physical and:

Answer: D — Mental-perceptual

Some people might incorrectly choose A, cognitive, because they may believe that riding only involves physical skills. However, riding also requires cognitive and mental-perceptual abilities, such as problem-solving, decision making, and spatial awareness. Option B, mechanical, is incorrect because it only pertains to the movement of the body and not the other aspects of riding. Option C, visual, is incorrect because it only involves one aspect - eyesight - and not the other important skills needed for riding. Therefore, the most accurate answer is D, mental-perceptual, as it encompasses the mental and perceptual skills necessary for safe and enjoyable riding.