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. 2 million barrels per day, $100, $60 million
B. 4 million barrels per day, $80, $160 million
C. 6 million barrels per day, $60, $60 million
D. 8 million barrels per day, $40, $20 million