Let's Say You Have a Hungry Cat in Your Kitchen

Let's say you have a hungry cat in your kitchen.You use your electric can opener,which makes a rather loud sound,to open a can of cat food.You have done this many times before.The hungry cat runs toward the plate of food when it sees it being set on the floor.In this example,running toward a plate of food when set in front of the cat is a/n

A) conditioned stimulus.
B) conditioned response.
C) unconditioned stimulus.
D) unconditioned response.