Answer: C.It provides an alternative energy pathway for the reaction to proceed.
Step-by-step explanation:
Activation energy is the extra energy that must be supplied to reactants in order to cross the energy barrier and thus convert to products.
A catalyst is a substance which increases the rate of a reaction by taking the reaction through a different path which involves lower activation energy and thus more molecules can cross the energy barrier and more molecules convert to products.
Thus catalyst speeds up the reaction and does not increase the total amount of product formed.
The catalyst itself does not take part in the chemical reaction and is regenerated as such at the end.