What Do Classical Conditioning,operant Conditioning,and Cognitive Learning All Have in Common

Multiple Choice

What do classical conditioning,operant conditioning,and cognitive learning all have in common?

A) Each is based upon the law of effect.
B) These forms of learning were once thought to be valid explanations of how we learn, but now are considered by psychologists as inadequate.
C) These forms of learning are common in animals, but rare in humans.
D) These are all forms of learning.