The statement that best describes how photosynthesis and cellular respiration are related to each other is:
**B. Products of one process are used as some of the reactants for the other process.**
In photosynthesis, plants convert carbon dioxide and water into glucose and oxygen using energy from sunlight. In cellular respiration, plants (and other organisms) use the glucose and oxygen produced in photosynthesis to produce energy in the form of ATP, generating carbon dioxide and water as byproducts. Thus, the products of photosynthesis serve as the reactants for cellular respiration and vice versa.