The correct answer is B.
Edward Thorndike was an American psychologist. He contributed greatly to the behavioral psychology field and his research had big impact on education, especially with his theory of the law of effect.
He devised an experiment in which he used a puzzle box to test the laws of learning. He put a cat in the box, which was encouraged to escape to reach a piece of fish outside the box. The cat tried many ways to escape but eventually stumbled upon the lever that opened the box. In successive trials the cat would learn the pressing the lever would have favorable consequences and it would adopt this behavior.
This experiment led Thorndike to put forward the law of effect. It stated that any behavior that is followed by pleasant consequences is likely to be repeated. Any behavior followed by unpleasant consequences is likely to be stopped.