Fred's parents are very inconsistent with their childrearing rules. Most of the time Fred can climb on the furniture but sometimes he can't. Fred is sometimes allowed to stay up until he falls asleep on his own, but sometime his parents will demand that he go to bed at an earlier time. Fred frequently throws temper tantrums when he can't get his way, and his parents typically give-in to his demands, although sometimes they don't. Fred's parents can't understand why he isn't a better-behaved child. Fred's parents are reinforcing his negative behaviors on a
A. fixed ratio schedule
B. fixed interval schedule
C. partial reinforcement schedule
D. continuous reinforcement schedule