Answer:
It is greater than the mass of oxygen formed.
Step-by-step explanation:
Photosynthesis is the process of using light energy to convert carbon dioxide and water to glucose and oxygen.
6CO₂ + 6H₂O ⟶ C₆H₁₂O₆ + 6O₂
Mass of CO₂ + H₂O = mass of C₆H₁₂O₆ + 6O₂
Subtract the mass of glucose from the right-hand side but not the left. Then
Mass of CO₂ + H₂O > mass of O₂
A is wrong, because glucose is formed, not used.
Bb is wrong, because oxygen is formed, not used.
C is wrong, because the total mass of reactants is greater than just one of the products.