The correct response is:
Photosynthesis needs a higher amount of energy to activate the reaction because the products are at a lower energy state than the reactants.
This is because photosynthesis is an endothermic process that requires energy (from sunlight) to convert carbon dioxide and water into glucose and oxygen. The activation energy is thus higher for photosynthesis since the products, glucose and oxygen, are at a higher energy state than the reactants. In contrast, cellular respiration, being exothermic, releases energy as glucose is broken down to produce carbon dioxide and water, and requires less activation energy.