Answer:
B. Conditioned stimulus
Explanation:
The "learning" process occurs when a certain stimulus is associated with a certain outcome.
For example, let's say that initially a person give no reaction every time he hears the sound of a bell.
We place that person in a solitary room and suddenly surprise him with a loud sound from behind right after the sound of the bell. Over time, that person will associate the bell with the loud sound and will flinch every time He hears a bell. This is what considered to be the learned reaction.
