The adjacent table shows the demand and revenue conditions in the world oil market. Assume that firms produce under constant-cost conditions, in which MC = ATC. Quantities are in millions of barrels per day. Plot this data on a sheet of graph paper. Answer the next 2 questions on the basis of this information. Q oil/ barrels Price/ MC = barrel MR ATC 0 $120 $40 2 100 $80 40 4 80 40 40 6 60 0 40 8 40 -40 40 Assume that the firms operate as purely competitive sellers (a purely competitive industry). In the long run, equilibrium price equals a. b. C. , quantity equals $100, 2 million barrels per day, $60 million $80, 4 million barrels per day, $70 million $60, 6 million barrels per day, $20 million , and profits total *d. $40, 8 million barrels per day, $0 million Suppose that the firms collude and become a cartel. The best level of output for the cartel as a whole is the price equals _, and profits total a. *b. C. d. 2 million barrels per day, $100, $60 million 4 million barrels per day, $80, $160 million 6 million barrels per day, $60, $60 million 8 million barrels per day, $40, $20 million