the answer is A. fordowne
fordowne is the least expensive brand to buy because it is 31.25 and the rest of the deals all come to a cost of 33 dollars.
2 dollars off when three 2 liter bottles are purchased. - fordowne.
2.75x3 is 8.25 - 2 is 6.25
6.25 for 6 liters
6 times 5 is 30
so 6.25 times 5 is 31.25
the lowest deal
if you want any other explanations i'll be happy to give them to you