For Years, Economists Believed That Market Structure Explained the Ability

For years, economists believed that market structure explained the ability of some firms to earn economic profits.Today, economists and business strategists put greater emphasis on

A) the number of years a firm has been in business and the average price of the products sold by the firm.
B) the number of countries in which a firm conducts business and the number of employees the firm has in each country.
C) the characteristics of individual firms and the strategies their managements use to continue to earn economic profits.
D) the size of a firm relative to the industry average and the number of firms in the domestic industry.