Question

Which of the following is true of photosynthesis?

A. Most reactions within this process are exothermic.
B. Oxygen is a reactant.
C. Carbon dioxide is a reactant.
D. Water is a product.

Answer 1

Equation for photosynthesis:

carbon dioxide + water ---> glucose + oxygen

Since sunlight is needed, it is an endothermic reaction. 
From the equation, it is noted that carbon dioxide is a reactant. 

Ans: C

Answer 2

I believe the answer is B......