Answer:
C; Oxygen concentration
Explanation:
Oxygen is product, not a reactant in photosynthesis. Light and carbon dioxide are reactants, and extreme temperatures can denature the plant.
Knowing the fact that around sixty percent of the human body is water, which consists of two hydrogen atoms and one oxygen atoms, and that other biomolecules like proteins also have oxygen atoms in their structure it's not a surprise that the percentage of oxygen in the human body mass is that high.
Even though there are two hydrogen atoms and only one oxygen atom in the water molecule, the oxygen atom has 16 times more mass than the hydrogen atom and therefore has a bigger contribution to the overall body mass.
B. Deforestation is the answer
Ammoniate would be your answer.
Enzyme speed up the reaction and provide alternative reaction pathway,they accelerate the reaction and convert reactants into products