Answer:
B. maximum attainable
Explanation:
The production possibilities frontier (FPP) is a graphic representation of the maximum quantities of production that an economy can obtain in a given period using all the resources available to it.
In an economy that has thousands of products, the alternatives to produce one or the other good and how much of each are very large. When an alternative is chosen, it means that other possibilities are being given up. The relationship between what we choose and what we give up is the opportunity cost.