Joseph goes out with his friends for pizza. Unbeknownst to him, he is coming down with a stomach virus. When the nausea associated with the virus kicks in, he vomits. Now, Joseph cannot even look at a pizza without feeling nauseous. In this example, the conditioned stimulus is .

In this example, the conditioned stimulus is the pizza.

Explanation:

The conditioned stimulus can be described as a stimulus which previously was normal. After becoming exposed to an unconditional event, the conditional stimulus starts to trigger a different response or approach.

For example, the scenario described in the question, eating or seeing pizza was normal for Joseph. After encountering an unconditional event, the pizza started to trigger an abnormal kind of response in Joseph. Hence, pizza is the conditional stimulus here.

i think the answer is true : ))