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.
Photosynthesis is an endothermic reaction where light energy is absorbed to convert carbon dioxide and water into glucose and oxygen, thus requiring a higher activation energy. In contrast, cellular respiration is an exothermic reaction, where the breakdown of glucose releases energy, and therefore has a lower activation energy relative to the energy required for photosynthesis.