If the four-firm concentration ratio for industry X is 80,

A) the four largest firms account for 80 percent of total sales.
B) each of the four largest firms accounts for 20 percent of total sales.
C) the four largest firms account for 20 percent of total sales.
D) the industry is monopolistically competitive.

Four-Firm Concentration

A metric used to assess the level of market concentration and competition, calculated as the total market share held by the four largest firms within an industry.

Total Sales

The total revenue generated from selling goods or services over a particular period, before any deductions such as returns or discounts.