Answer:
operant conditioning.
Explanation:
Operant conditioning is the term given to a learning method, where an individual is trained to exhibit specific behavior after an element is presented to him. When this individual exhibits the required behavior, he receives a reward, otherwise he receives a punishment.
In the example given in the question above, the cat Charlie underwent an operative conditioning process, as it was trained to be in the kitchen whenever it heard the noise of the electric can opener. When Charlie answered that noise, it got a food that it liked. For this reason, whenever it hears the noise, it goes to the kitchen waiting for the reward.
