The correct answer is positive reinforcement.
Operant conditioning is a psychological term referring to the learning process based on the modification of a specific behaviour through punishment or reward. The term was introduced by the behaviourist B.F. Skinner, who proposed that through presenting negative or positive stimuli a person can learn or modify a behaviour. A reward represents a positive reinforcement of the behaviour and a punishment a negative reinforcement. Positive reinforcements are offered to a person after performing a specific behaviour or task that we want to reinforce. In this example, Dan received fan mails which express support and praise and this is a positive reinforcement for the articles that he writes.
