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.
In photosynthesis, energy from sunlight is used to convert carbon dioxide and water into glucose and oxygen, and it requires an input of energy, making it endothermic. The products (glucose and oxygen) are at a higher energy state compared to the reactants (carbon dioxide and water). This means more activation energy is needed to initiate the reaction.
In contrast, cellular respiration is exothermic, releasing energy as glucose is broken down into carbon dioxide and water, with the products being at a lower energy state than the reactants, indicating that it typically requires less activation energy to start.