Final answer:
The theory that Thorndike developed is known as operant conditioning. Animals learn to associate a behavior with its consequences in operant conditioning.
Step-by-step explanation:
The theory that Thorndike developed from his observations of cats escaping from a 'puzzle box' to obtain a piece of fish is known as operant conditioning (B) in psychology. In operant conditioning, organisms learn to associate a behavior with its consequences. The behavior is gradually modified by positive or negative reinforcement. For example, in the experiment with the cats, Thorndike found that the cats' behavior of escaping from the puzzle box was reinforced by the reward of obtaining the fish.