The United States became a rich industrial nation toward the end of the 1800s. There were more goods, more services, more jobs, and a higher standard of living. There was more of everything, including problems. One problem was monopoly — that is, be the only seller of a certain line of products or a service. In some cases, several companies that manufactured the same product would agree not to compete with one another. They would all agree to charge the same price. These arrangements made it impossible for customers to shop around for lower prices for certain products.Some people decided that huge corporations had too much power and controlled too many markets. Because of their wealth and power, they could see to it that government passed laws favorable to them. Many people believed that monopoly and price fixing were bad for customers anti bad for the country so that they should be broken up.Finally, the national government and some states passed laws that placed limits on corporations and big companies. These laws made it illegal for companies to make agreements to charge only a certain price. Later on the national government forced monopoly to be broken up.Such laws and government action didn’t entirely do away with monopolies. Nor did they stop the growth of huge corporations. But they did show that American people had decided that some of the changes that had occurred were harmful. According to the laws, companies ().

A. were not allowed to control the markets
B. could not force the customers to buy their products
C. should have fixed prices for their products
D. must produce the same kind of goods for the same market