Which statements are true regarding economies of scale?Choose one or more:A.When a firm has a natural monopoly, it has that type of monopoly because of economies of scale.B.To maximize profits, a monopoly that occurs because of economies of scale should produce an output so that marginal revenue equals marginal costs.C.Economies of scale typically cause an industry to be perfectly competitive.D.A firm that has economies of scale sees its average total costs decrease when production increases.