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