One Crucial Difference Between the Oligopolists and Perfect Competitors Is

One crucial difference between the oligopolists and perfect competitors is that

A) perfect competitors are not concerned with maximizing profits.
B) nonprice competition plays a central role in oligopoly.
C) the price charged by oligopolists is less than that charged by perfect competitors.
D) perfect competitors advertise more heavily.
E) oligopolies are less prone to collusion.