Jane had leukemia as a child and had to undergo numerous bouts of chemotherapy. The chemotherapy always made her nauseous. As she underwent a year of treatment, the waiting room started to make her nauseous. The waiting room became the:

The waiting room became the conditioned stimulus.

Explanation:

Conditioned stimulus is the reflexive behaviors or the learned behavior.

This stimulus may be defined as a neutral stimulus that with some time and some training will evoke a response by continuously being associated with any other natural occurring stimulus.

a, i am pretty sure.

when a reversible reaction is occurring in both directions at the same rate; the products and reactants do not change in concentration. a chemical reaction where the compound is broken into its constituent parts.