19. Which statement describes the relationship between the reactants of
photosynthesis and the products of cellular respiration?

A. The products of cellular respiration are the products of
photosynthesis.

B. The products of cellular respiration serve as the reactants
photosynthesis.

C. The reactants of cellular respiration are the reactants of
photosynthesis.

D. Cellular respiration and photosynthesis are unrelated.