The process of respiration is: (a) An oxidation reaction which is endothermic (b) A reduction reaction which is exothermic (c) A combination reaction which is endothermic An oxidation reaction which is exothermic

Option (d) is the answer. During digestion the food what we have taken breakdown and gives energy. If we are having carbohydrate content food items, it break downs to glucose and it combines with oxygen to give energy and thus addition of oxygen takes place and energy is also released