In order to find the answer just divide the prices by the ounces.
Lets start with A. $5.25 divided by 12 is 0.4375 per ounce. Now B $5.50 divided by 13 is 0.423 per ounce Now C 3.45 divided by 3.5 is 0.9857 per ounce Now D 5.75 divided by 14 is 0.4107 per ounce
Now all you do know is look at which price per ounce is the cheapest.
