Classical (Respondent) Conditioning was first demonstrated by which of the following scientists through his experiments?

Classical (Respondent) Conditioning was first demonstrated by Ivan Pavlov through his experiments with dogs.Pavlov observed that dogs would salivate not only when presented with food (the unconditioned stimulus) but also when they heard a bell that was consistently paired with the food, eventually leading them to salivate at the sound of the bell alone. This phenomenon became known as classical conditioning.