Final answer:
The waiting room became the conditioned stimulus (CS) for Edelia, triggering a conditioned response of nausea due to classical conditioning from her chemotherapy treatments.
Step-by-step explanation:
When Edelia started to feel nauseous just by entering the waiting room, the waiting room became the conditioned stimulus (CS). This change is a result of classical conditioning, a learning process that occurred during Edelia's chemotherapy treatment. Chemotherapy is known to often cause nausea, a reaction that, after repeated exposure, can become associated with the sights, sounds, and smells of the environment where the treatment is received.
As a result of this association, even without the actual administration of chemotherapy, entering the waiting room alone can provoke a nausea response in Edelia, which in the context of classical conditioning, is known as the conditioned response (CR).