Answer:
[tex]\boxed {\boxed {\sf It \ lowers \ the \ activation \ energy \ and \ it \ speeds \ up \ chemical \ reactions }}[/tex]
Explanation:
A catalyst is a substance that increases the rate of a chemical reaction. Some examples are enzymes and acid-base catalysts.
They can do this by lowering activation energy (the energy needed to undergo a reaction) or modifying a certain mechanism in the reaction.
Catalysts are unique because they aren't consumed or used up in a reaction. They can be reused many times.
So, based on the information above, catalysts do not increase the activation energy or get consumed in the reaction. That leaves two correct answers: they lower the activation energy and speed up chemical reactions.
