Which Would Be a Qualification to the View That Oligopoly

Which would be a qualification to the view that oligopoly is allocatively and productively inefficient?

A) Less foreign competition has stimulated more price competition in oligopolies.
B) Oligopolies are less technologically competitive, so they lose market share.
C) Oligopolies may purposely keep prices below short-run profit-maximizing levels to bolster barriers to entry.
D) The more collusive practices of oligopolies lead to more profit-sharing among firms in the industry.