The Four-Firm Concentration Ratio in an Industry Is 75 Percent

Multiple Choice

The four-firm concentration ratio in an industry is 75 percent. Total sales in the industry are $800 million and total economic profit in the industry is $500 million.Normal profit for each firm is zero.
From this information we know that

A) economic profit of any four firms is at least $667 million.
B) total sales from the four largest firms is $600 million.
C) economic profit of the four largest firms is $375 million.
D) total sales from any four firms is at least $1,067 million.
E) economic profit of the four largest firms is $500 million.