The correct answer is Photosynthesis in plants.Concept:Chemical reaction:A process in which one or more substances, the reactants, are converted to one or more different substances, the products.Substances are either chemical elements or compounds.A chemical reaction rearranges the constituent atoms of the reactants to create different substances as products.Explanation:Endothermic reaction:A chemical reaction in which the reactants absorb energy and get converted into products. Photosynthesis in plants: It occurs in green plants in the presence of sunlight and chlorophyll.The reactants carbon dioxide and water are converted into glucose and oxygen.CO2 + H2O + Sunlight(Heat) ? C6H12O6 + O2?Solar energy is converted into chemical energy.Since energy is being consumed in photosynthesis, it is termed an endothermic reaction. Additional Information? Exothermic reaction:A chemical reaction in which heat energy is released. Examples: Burning of natural gasConversion of vegetable matter into compost?Burning of magnesium ribbon in the air.