I just need short answer not an explanation

3. The Trouble With Tuna

Brian was looking forward to lunch. His mother had prepared a tuna sandwich. Unfortunately, the mayonnaise she used had been left out too long and was spoiled and rotten. Not long after eating, Brian felt extremely nauseated and had to rush to the bathroom. Thereafter, the mere mention of a tuna sandwich would send Brian scurrying to the bathroom. Identify the following variables of classical conditioning in this scenario:

Unconditioned Stimulus (US)
Unconditioned Response (UR)
Conditioned Stimulus (CS)
Conditioned Response (CR)