Answer :
A catalyst isn't used up in the reaction. It is only used to speed up the process of the reaction, but it isn't used up to form any new compounds
Answer: Option (a) is the correct answer.
Explanation:
A catalyst is the substance which helps in increasing the rate of a reaction without itself getting consumed in the reaction.
A catalyst changes the path of reaction so that molecules with lower energy can easily participate in the reaction. As a result, formation of products increases.
Thus, we can conclude that out of the given options, a catalyst is not used up in a reaction.