When a classical conditioning paradigm first starts, there is stimulus which does not elicit any responses at first. This is the C. Conditioned stimulus (CS).
This is a stimulus that does not cause any reaction in a person or organism at first.
As the classical conditioning continues, the CS will then be associated to the subject in such a way that they will begin to respond in a certain way when the CS is introduced.
Find out more on the Conditioned stimulus at https://brainly.com/question/24868138.