In one of the steps of the carbon cycle, a person exhales a molecule of
carbon dioxide (CO2) into the atmosphere. Which of the following is
most likely to happen next to the atom of carbon in this molecule?
A. It may be used as part of a sugar in a plant.
B. It may become part of a protein in an animal.
C. It may be consumed as a fossil fuel is burned.
O D. It may be decomposed into carbon and oxygen by a bacterium.