The correct answer is D. A conditioned stimulus
Step-by-step explanation:
In psychology and behavior, a conditioned stimulus refers to a stimulus that can be a sound, image, situation, etc. that leads to a non-natural response as the response as well as the stimulus have been conditioned through specific experiences. This also means a conditioned stimulus was once a neutral stimulus that did not lead to a response. In the case of Bryson, the bell is a conditioned stimulus, because before the fire this was a neutral stimulus which means when Bryson heard the bell he did not have a specific response; however, due to the fire the sound of the bell triggers a specific fear response and therefore the stimulus has been conditioned due to a specific experience.