Option A is the right answer that Free-market economies use prices to distribute goods, services, and resources.
In economics, a Free-market is an idealized system, where the prices for goods and services are determined by the open market forces( demand and supply). Therefore the government plays no role in price fixing in the open market competition. The most important and the basic feature of this type of economy is that only the people have the right to purchase goods and services with its adequate control over resources.
