22. Compared to a monopolistically competitive industry, an oligopoly has

a. a higher Herfindahl–Hirschman Index, fewer firms, and more barriers to entry.

b. a higher Herfindahl–Hirschman Index, more firms, and more barriers to entry.

c. a higher Herfindahl–Hirschman Index, fewer firms, and fewer barriers to entry.

d. a lower Herfindahl–Hirschman Index, fewer firms, and more barriers to entry.

e. a lower Herfindahl–Hirschman Index, more firms, and more barriers to entry.