McCall is conducting another experiment.In group 1, she stops playing an irritating noise if the kids clean up their room.

Dr. McCall is conducting another experiment. In group 1, she stops playing an irritating noise if the kids clean up their room. In group 2, there is no irritating noise before or after kids clean their room. Her results show that kids in Group 1 clean their room more often. Which type of reinforcement is being used in group 1 this time?

negative reinforcement 

punishment 

positive reinforcement 

partial reinforcement