Which of these situations reinforces undesirable behavior?

Question

A. Promising a whining five-year-old a treat if he will stop whining and come alongb B. Holding a competition to see who has the most organized cubby C. Saving up stars to trade in for stuffed animals D. Giving a child a star for cleaning up the game area promptly when asked 

B.

Answer 1

I was wrong last night. The Answer is A.

Answer 2

Ok.
Thank you :)