Answer: Option (4) is the correct answer.
Explanation:
Activation energy is the minimum amount of energy required by reactant molecules to undergo a chemical reaction.
Whereas a catalyst is defined as the substance that helps in increasing the rate of reaction by decreasing the activation energy without itself getting consumed in the reaction.
When a catalyst decreases the activation energy then molecules with lesser energy become able to participate in the reaction and thus, products are obtained at a faster rate. Hence, a catalyst increases the rate of a reaction.
Thus, we can conclude that a catalyst works by decreasing the activation energy required for a reaction.
