You have to divide the amount of money by the pack number. So A would be 0.25 cents per soda. B would be 0.25 cents per soda. C would be 0.26 cents per soda. And finally, D would be 0.22 cents per soda. Therefore Store D would be the best buy.
Hope this helps!!!!!!!!! ◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊◊