Question

with regard to the ppf, an efficient point is a point that is outside the ppf. inside the ppf. on the ppf impossible to reach.

Explanation:

The Production Possibility Frontier (PPF) represents the maximum combination of two goods an economy can produce with its available resources and technology. A point on the PPF means all resources are fully and efficiently utilized (productive efficiency). Points inside the PPF are inefficient (unused resources), and points outside are unattainable with current resources. So an efficient point is on the PPF.

Answer:

C. on the PPF