You feel fine when you sit down in the classroom, but as soon as you hear the teacher’s announcement of a surprise quiz you immediately feel your pulse quicken and your stomach churn. Your reaction to the teacher's announcement is most likely a(n)

Your reaction to the teacher's announcement is most likely a(n) conditioned response.

Explanation:

In classical conditioning, a conditioned response is the response elicited after a neutral stimulus and a conditioned stimulus are associated. A simple example would be the following: You drive by a tree every day, but you feel nothing in particular while doing so. One day, you almost crash the car into that very tree because the road is slippery. Because of that, you feel stressed. Your heartbeat increases. Now, every time you drive by that tree, you feel anxious and stressed, with palpitations in your chest. This reaction to seeing the tree is the conditioned response. The tree was a neutral stimulus that ended up associated with the stress of the (almost) accident.

If your reaction to hearing a surprise quiz will take place is to feel your pulse quicken and your stomach churn, you have probably associated quizzes with something bad. Maybe, one time, you did really badly at a surprise quiz, which caused you to feel nervous. Now, every time there is a quiz, that reaction is elicited, which means it is a conditioned response.

when your a dog and you need a bone.   go and eat a rabbit

the density would be a smaller number.