Final answer:
The behavior that is reinforced after varying periods of time is known as Variable Interval, while the behavior associated with an unpredictable number of responses is under a Variable Ratio schedule, exemplified by the operations of slot machines. The correct option is D.
Step-by-step explanation:
Behavior that is reinforced after periods of time, with the time span varying from one time to the next, is called Variable Interval. This contrasts with a fixed interval reinforcement schedule.
where behavior is rewarded after a set amount of time, and a fixed ratio reinforcement schedule, where a set number of responses must occur before a behavior is rewarded. An example of a variable ratio reinforcement schedule.
Which is more similar to the question but based on the number of responses rather than time, is the operation of slot machines in casinos.
This type of schedule leads to a high and steady rate of responses, as the reinforcement is given out after an unpredictable number of desired behaviors, making it highly resistant to extinction. The correct option is D.