The correct answer to this open question is the following.
In a free enterprise system, what drives individuals to risk their savings in a business venture is the opportunity to get profits and get rich.
In the free enterprise system, people open many businesses in order to make a profit and get rich. In a free-market economy like the one of the United States, free competence allows people to chose from many companies to get a product. So businessmen open shops, restaurants, factories, and companies to provide goods and services that satisfy consumers who pay a fair price to satisfy their needs. The more consumers a company has, the highest the percentage of profit.