Which of the Following Describes Why an Economy's Production Possibility

Multiple Choice

Which of the following describes why an economy's production possibility curve is "bowed" outward?

A) The opportunity cost of production of a good is constant as more of it is produced.
B) Some resources are more substitutable among productive tasks than others.
C) The opportunity cost of production of a good decreases as more of it is produced.
D) Resources cannot be substituted between productive tasks.