John Has to Give His Cat Garfield a Pill Every

Multiple Choice

John has to give his cat Garfield a pill every day.He always opens up the pill bottle (which makes a popping sound) and removes one pill before giving it to Garfield,and he follows this by giving him a treat as a reward.After a while,John notices that when he opens up the pill bottle,Garfield comes running to him right away.In this example,the __________ is the conditioned stimulus.

A) sound of the pill bottle opening
B) pill-taking
C) cat running out
D) treat