In which reinforcement schedule is a reinforcement given for the first response after an unpredictable amount of time has elapsed

A)  fixed interval schedule
B)  variable ratio schedule 
C)  fixed ratio schedule
D)  variable interval schedule

Variable Interval Schedule

A reinforcement schedule where rewards are provided after an unpredictable time interval, leading to more consistent behavior.

Fixed Interval Schedule

A type of reinforcement schedule in operant conditioning where the first response after a fixed time period is rewarded.

Variable Ratio Schedule

A reinforcement schedule in which a response is rewarded after an unpredictable number of responses, promoting high and stable rates of the response.