Which of the following statements about Ivan Pavlov is true?
-He is considered the founder of behaviorism.
-He is famous for demonstrating the principles of operant conditioning: The motivation for a behavior happens after the behavior is demonstrated.
-He is known for establishing the principles of classical conditioning.
-He placed hungry rats in a maze with no reward for finding their way through it, and he studied a comparison group that was rewarded with food at the end of the maze.

He is known for establishing the principles of classical conditioning.

Explanation:

Ivan Pavlov was a Russian psychologist and is known for his development of classical conditioning and his popular experiment with the dog. Ivan Pavlov's classical conditioning found that objects or events could bring about conditioned response if associated or paired in such a way to elicit response. His experiment with his dog using classical conditioning brought about a conditioned response in his dog

i think it is the third one.