1
 If we compare photosynthesis and cellular respiration 
 in terms of energy
 conversions involved, we observe that in-
 A
 photosynthesis, carbon dioxide is used to produce energy.
 B
 photosynthesis, energy is used to produce oxygen.
 с
 cellular respiration, carbon dioxide is used to produce energy.
 D
 cellular respiration, energy is used to produce oxygen.