Key Figure in Behaviorism

As psychology developed as a formal discipline in the late 19th and early 20th centuries, various perspectives emerged, each influencing the understanding of human behavior and mental processes. One of these perspectives, behaviorism, focused on observable behaviors rather than internal mental states. It gained prominence through the work of several key figures.

Which of the following psychologists is best known for his contributions to behaviorism and is credited with the famous experiment involving a dog and conditioning?