Researchers use radioisotopes to study the metabolism of plants. This would then be followed by fractionation to determine which biomolecules accumulated the radioisotopes. If a plant were exposed to 13cO2 over a long period,

where would the 13C ultimately be found?

CO2 is not stored by photosynthetic plants, so 13C would not accumulate.

O It would be found in fats/lipids, because they are used as the energy storage molecule for plants.

O All biomolecules would include 13C as a result of metabolic processes after photosynthesis.

O It would be found in carbohydrates like starch, because they are used as the energy storage molecule for plants.