Respuesta :
Answer: a.intestines and digestive process of dogs.
Ivan Pavlov was a Russian physiologist known for his work in classical conditioning. Pavlov won the Nobel Prize for Physiology or Medicine in 1904.
Pavlov made his discovery while studying digestive glands at the Institute of Experimental Medicine in St. Petersburg. Pavlov was investigating the gastric function of dogs and children, when he noticed that dogs salivated before food was delivered to their mouths. This led him to investigate the response, which led to the development of his theory of conditioning.