Answer:
B. carbon dioxide.
Step-by-step explanation:
In cellular respiration, the products are carbon dioxide (CO2), water (H2O), and energy in the form of adenosine triphosphate (ATP).
In photosynthesis, carbon dioxide (CO2) is used along with water (H2O) and light energy to produce glucose (C6H12O6) and oxygen (O2).
So, if the question is about a product of cellular respiration that is also involved in photosynthesis, the correct answer would be:
B. carbon dioxide.
It plays a role in both processes, being a product of cellular respiration and a reactant in photosynthesis.