When voluntary exchanges in the markets determine decisions on production and consumption, the society's economic system is a:

capital in nature.

Explanation: In a capital market structure, the price of goods and services produced are determined by the market forces of demand and supply. In these economies private owners willingly makes exchanges to maximize their profits.

The production and consumption under such economies are purely determined by the market forces, as the intervention from Govt. is minimal.

answer; i do believe its (b) 12.5 years of age;