On Tuesday morning, Chloe prepared her typical breakfast of corn flakes with milk and a cup of coffee. However, instead of having grapefruit with her breakfast, she tried eating guava for the first time. Later, she became extremely ill. If her illness causes her to develop a conditioned response to one of her breakfast items, the conditioned response will MOST likely be to

guava, because it was a novel stimulus

Explanation:

On Tuesday morning, Chloe prepared her typical breakfast of corn flakes with milk and a cup of coffee. However, instead of having grapefruit with her breakfast, she tried eating guava for the first time. Later, she became extremely ill. If her illness causes her to develop a conditioned response to one of her breakfast items, the conditioned response will MOST likely be to guava, because it was a novel stimulus

Conditioned response is a reflexive response that has been learnt this occurs by putting together a neutral stimulus with another stimulus, this naturally orovikes a response. In this case she eating guava for the first time is a neutral stimulus and then she falling ill immediately is the potent stimulus( a stimulus not learnt z) this provokes a conditioned response that guave makes me ill.