The Herfindahl–Hirschman index is a measure of concentration found by:
A.
squaring the percentage market share of each firm in the industry.
B.
squaring the percentage market share of each firm in the industry and then summing the squared market shares.
C.
summing the percentage market shares of each firm in the industry.
D.
squaring the sums of the concentration ratios found in an industry survey of the largest four and largest eight firms.