Answer: better suited for the production of some goods than others.
Explanation: A ppf is more likely to be a downward-sloping curve that is bowed outward than a downward-sloping straight line because most resources are better suited for the production of some goods than others. The opportunity cost is increasing along the PPF, which means that as we increase the production of one good, more and more units of the other good have to be sacrificed. Increasing opportunity cost is why most PPF's are bowed outward.
