A Four-Firm Concentration Ratio of 75 Tells You That the Top

A four-firm concentration ratio of 75 tells you that the top:

A) firm in the industry produces 75 percent of the industry's output.
B) four firms in the industry produce 75 percent of the industry's output.
C) four firms in the industry produce 25 percent of the industry's output.
D) four firms in the industry earn 75 percent of the industry's profits.