Adam smith applied enlightenment ideas of reason to his economic philosophy of laisser-faire and a free market economy. which statement below best explains his concept of natural law in the government’s role in the economic lives of its citizens?

You didn't include statement choices, but my assumption is it's something like this:   The government stays out of business regulation to let the people operate as they please.

Explanation/context:

Adam Smith (1723-1790) was a powerful critic against what he called the "mercantile system" of his day, because it restricted trade and thus restricted economic growth.  The mercantile system believed the wealth of the world was a fixed amount, measured primarily in gold and silver accumulated.  The system promoted a nation selling its products abroad but not needing to buy from others, or imposing heavy tariffs if importing anything.  Colonies were crated to provide raw materials and resources to the mother country and a market for the mother country's products.  Commerce was heavily controlled by the government through charters granted to specific trading companies.

Adam Smith countered by advocating a free market -- the opportunity for all nations to increase their wealth by exchanging goods freely with one another according to what would become known as capitalist principles.  The "laissez-faire" terminology for this is a French term, which came from a French group of thinkers called the Physiocrats (meaning "rule by nature').  They and Smith were in agreement about getting government out of the business of controlling business.