Three of the Following Are Examples of Operant Conditioning

Three of the following are examples of operant conditioning.Which one is not?

A) Andrew gives his dog Maggie a scrap of food from his plate whenever Maggie begs at the dinner table.Before long, Maggie is by Andrew's side begging at every meal.
B) Bart uses obscene words when he speaks in class.His teacher scolds him for such language in front of his classmates.Much to the teacher's dismay, Bart's use of obscene words increases.
C) Carol's room has been a disaster area for more than a month, with toys and clothes lying about everywhere.Carol's mother has told her that, once the room has been cleaned, they will spend a day at the zoo.There is no noticeable improvement in Carol's housekeeping habits.
D) Daniel once went to visit the elderly woman next door, and she gave him a couple of homemade cookies.Now Daniel goes to see the woman almost every day after school and comes home a half an hour later still licking crumbs off his lips.