单选题 For which the following four-firm concentration ratios and Herfindahl-Hirschman indexes (HHI) indicates a highly competitive market?
Four-Firm Ratio HHI
①A. 5% 150
②B. 98% 9500
③C. 98% 150

A. ①
B. ②
C. ③

【正确答案】 A

【答案解析】For both the four-firm ratio and the HHI, the lower the market concentration measure, the greater the degree of competition.