Here are the options:
a. Vomiting
b. Dark red tablecloth
c. Feeling sick
d. Pizza
Answer:
b. Dark red tablecloth
Step-by-step explanation:
The conditioned stimulus is a previously neutral object (dark red tablecloth), which after becoming associated with the unconditioned stimulus (the pizza), then triggers a conditioned response (feels sick).
Liam's eventual association with the dark red tablecloth became on that special occasion when they ate pizza, which unfortunately made him feels sick.