Well let's see. Since product B is twice the amount of of product A, we'll have to see if product A is still cheaper if you get two bottles.
Product A(12 oz.)=$1.39 so just multiply the price by 2
(1.39)*2=2.78
So if you bought 2 bottles of Product A it would be $2.78, which is just one cent cheaper than getting the 24 oz bottle that is $2.79.
Therefore, Product A would be the better buy, but not by very much lol.