The answer would be A. carbohydrates (carbs) because carbs are generally composed of sugars and glucose (as an example) has the ratio between carbon, hydrogen and oxygen in a 1:2:1 ratio in its form: C6H12O6
These macromolecules are the ones that contain carbon, hydrogen (that is the reason of the name carbo hydrate), and oxygen.
The formula of them is based in water molecule (H2O), plus the atom of carbon. Actually is the carbon, the element that states the number of molecules of water. Their formulas is Cm(H2O)n. As an example is the glucose or fructuose, both with a formula C6H12O6.
with this proportion, the ratio will be 1:2:1 of carbon, hydrogen, oxygen.
