Answer:
a. a conditioned response.
Step-by-step explanation:
Ivan Pavlov was one of the famous psychologists who has discovered the classical conditioning experiment or theory while experimenting with dogs.
Conditioned response: The term conditioned response is a part of the classical conditioning theory or experiment, and is described as an unnatural behavior an is being learned by the human beings or an animal after becoming associated with a potent stimulus.
In the question above, the salivation in the given statement signifies a conditioned response.