Answer :
Answer:
fixed-interval
Explanation:
Fixed-interval schedule is considered as one of the four distinct types of reinforcement schedule in the operant conditioning theory which was introduced by B. F. Skinner. A fixed-interval schedule is referred to as a reinforcement schedule whereby the very first or initial response is being rewarded once a 'specified time amount' has been passed or elapsed.
In this case, Colin's behavior is reinforced on a fixed-interval schedule.