During the 1950s, Many Psychologists Were Becoming Discouraged with Behaviorism

During the 1950s, many psychologists were becoming discouraged with behaviorism, and cognitive psychology began to emerge. A major reason they were disappointed with behaviorism is that

A) it considered only psychological processes that are clearly observable.
B) it paid too much attention to individual differences.
C) it failed to develop objective methods of measuring behavior.
D) it focused too much on emotional factors, and not enough on observable behaviors.