There are 3 boxes of blueberry cereal at the store. Zoe wants to get the best buy, so she calculates how much each box of cereal costs per ounce to find which one is the least expensive.

Box A costs $3.68 for 23 ounces
Box B costs $4.62 for 33 ounces
Box C costs $2.72 for 16 ounces
What is the cost per ounce of the box that gives her the best buy?