ilut curve 5. In the United States today collusion is (LO2) a) illegal and does not exist b) illegal and does exist c) legal and does not exist d) legal and does exist 6. Which statement is true? (LO4) a) All firms in oligopolistic industries are large. b) Most firms in the United States are oligopolies. c) The crucial factor in oligopolistic industries is product differentiation. d) Most of our GDP is produced by oligopolies