Market Shares of All Eight Firms in an Industry Are

Market shares of all eight firms in an industry are 50 percent, 20 percent, 14 percent, 6 percent, 4 percent, 3 percent, 2 percent, and 1 percent.What is the Herfindahl index?

A) 90
B) 90²
C) 50² + 20² + 14² + 6²
D) 50² + 20² + 14² + 6² + 4² + 3² + 2² + 1²
E) the sum of the market shares of the four largest firms