Multiple choice Carbohydrates are composed of Carbon, Hydrogen and Nitrogen Nitrogen, Carbon and Oxygen Oxygen, Hydrogen and Nitrogen Carbon, Hydrogen and Oxygen Reveal answer Fill a bubble to check yourself D Correct answer Explanation A carbohydrate is an organic compound with the empirical formula Cm(H2O)n (where m could be different from n); that is, consists only of carbon, hydrogen, and oxygen, with a hydrogen: oxygen atom ratio of 2 : 1.