Answer:
The answer is IV. opportunity cost
Explanation:
A production possibility curve or production possibility frontier is a curve that shows the possible combinations of different commodities that can be produced in a given economy, given the prevailing level of technology
Opportunity cost on the other hand is the expression of cost in terms of forgone alternative.
However the production possibility curve is directly related to opportunity cost because the PPC involves sacrifice in the production of one commodity in order that another one will be produced. Also when preparing a PPC, the downward slope show that there is an opportunity cost involved in the production of more of a commodity.
From the explanation above it is clear that the concept of opportunity cost can be illustrated using the PPC