Respuesta :
Answer: Option (C) is the correct answer.
Explanation:
A catalyst is a substance which helps in increasing the rate of a chemical reaction by lowering the activation energy without itself getting consumed.
When reactant molecules does not have enough energy to cross the activation energy barrier then catalyst lowers the activation energy barrier. As a result, molecules with less energy are able to participate effectively that leads to increase in rate of reaction.
Hence, we can conclude that catalysts affect the energy of reactions as they lower the activation energy required for the reactions to take place.

Answer:
C. They lower the activation energy required for the reactions to take place.is the correct answer.
Explanation:
catalysts affect the energy of reactions as they lower the activation energy required for the reactions to take place.
A catalyst is a substance that helps in enhancing the chemical reaction rate by reducing the activation energy without getting used.
When the reactant does not have sufficient energy to meet the activation energy limit then the catalyst reduces the activation energy limit.
As a result, the molecules with weaker energy are able to compete efficiently which leads to an increase in the rate of reaction.