In a market economy:

workers are directed by government planning boards to produce what is in societies best interest.

businesses design their plans to maximize their profit and the market is relied upon to see that individual self-interest is consistent with society's interest.

government sets prices to make necessities affordable because it is in society's best interest to make necessities affordable.

government owns the means of production so that it can produce what is in society's best interest.

The answer is,

businesses design their plans to maximize their profit and the market is relied upon to see that individual self-interest is consistent with society's interest.

Explanation:

In a market economy, government does not intervene the automatic market process which happens because of the supply and demand. The individual decisions are coordinated with the price mechanism and this is what Adam Smith called as the "invisible hand".

The price mechanism is the automatic force behind the resource allocation and distribution.

The government may intervene however, to make adjustments to periodic failures in the market.

businesses design their plans to maximize their profit and the market is relied upon to see that individual self-interest is consistent with society's interest.

Explanation:

A market economy refers to the economic system where the production of goods and services depends on the abilities and desires of the market participants. The market economy allows the laws of supply and demand to dictate the types of goods and services to be produced and their prices. The government plays minimal or no role in economic transactions.

Private citizens or entrepreneurs own, direct, and coordinate the factors of production with profit motives. The market economy is characterized by the efficient and innovative use of resources by entrepreneurs as they compete for profits. Buyers always have a wide variety of goods and services to select from, while sellers use their creativity to maximize profits.