Answer:
A. The reactants absorb heat because they have less energy than the products.
Explanation:
According to the law of conservation of energy, energy can neither be created nor destroyed.
The given equation of the chemical reaction indicates that the reaction is endothermic as heat is absorbed by the reactants. In an exothermic reaction heat is released by the products.
In an endothermic reaction initially the heat of the reactants in less than the products, thus according to the law of conservation of energy, the reactants absorb heat such that there is equal amount of heat on both the reactant and product side.
