Dillon is four years old, and his parents want to teach him to say "" and " you." they will be most successful in altering dillon’s behavior if they use
a. higher-order conditioning.
b. non-contingent reinforcement.
c. classical conditioning.
d. operant conditioning.

Operant conditioning

Explanation:

Children at this age haven't developed a sense of empathy or the ability to see the world from the other people's perspective and they focus on the short-term and direct consequences of their acts.

Operant conditioning is a type of learning technique through rewards and punishments for behavior. When the person has the desired behavior we give him/her a reward for it, also when  the person has an undesired behavior, the person is punished.

Dillon's parents want to teach him to say "please" and "thank you".

Since at this age, Dillon's will focus in the immediate consequences of his acts, Operant conditioning would be the best choice since it focuses on rewards that are given when the desired behavior is observed.

Dillon's parents could give him rewards every time he says "please" and "thank you" and this way they will most likely succeed.