The Production Possibility Curve Under Increasing Opportunity Costs Is Concave

Multiple Choice

The production possibility curve under increasing opportunity costs is concave to the origin because

A) The opportunity cost of leaving a unit of one commodity to have an additional unit of the other is constant
B) Each country completely specializes in the production of only one commodity after trade
C) They are the same at all points
D) When a country in the production of one commodity in which it has comparative advantage, its opportunity costs increases