Which of the following are true about the equilibrium in an oligopoly market structure?

A) Firms in an oligopoly are highly interdependent, and their decisions affect each other’s outcomes.
B) Oligopolistic firms produce at the point where marginal cost equals average cost to maximize profit.
C) The existence of barriers to entry prevents new firms from entering the market, ensuring the dominance of existing firms.
D) Firms in an oligopoly market tend to engage in non-price competition to differentiate their products.