Answer:
A. positive reinforcement
Explanation:
Assuming Adam dislikes veggies and likes ice cream...
Adam is being conditioned to eat his vegetables via positive reinforcement.
Punishment would be a negative result from eating him vegetables.
Negative reinforement is pretty much the same thing as punishment.
Extinction would mean he stopped getting what he wanted for the action he didn't like (eating veggies) and stopped doing it.
