The correct answer is: C. Based on the preference of the customers.
In a free market economy, the distribution of resources is determined by the preferences of the customers. Businesses produce goods and services that they believe customers will want to buy, and customers purchase the goods and services that they believe will best satisfy their needs and wants. This process of supply and demand determines the prices of goods and services, and the prices in turn determine how resources are allocated.
Option A is incorrect because voting is not a factor in the distribution of resources in a free market economy. Businesses are not elected by the public, and they do not have to answer to the public for their decisions.
Option B is incorrect because there is no central planning authority in a free market economy. The government does not control the production or distribution of goods and services.
Option D is incorrect because the profit of a firm is not the only factor that determines the distribution of resources in a free market economy. The preferences of the customers are also a major factor.