Correct Answer: B
Explanation:
Choices A and D are incorrect – enzymes reduce the amount of energy needed, they do not create the reaction or provide the energy. Choice B is correct – the definition of a catalyst “speeding up a chemical reaction by lowering the amount of energy needed.”Choice C is incorrect – enzymes are not involved in reactions, they are not a reactant nor become a product, which is why they can be reused again once a reaction has finished.