Answer:
Reduce marginal costs so that they equal marginal revenue.
Step-by-step explanation:
Regardless of whether the producer is a monopolist, oligopolist, or in perfect competition, the profit-maximizing quantity is where marginal revenue equals marginal costs, or in other words the cost of producing the next unit of output is equal to the revenue earned by the next unit of sales. Any output before this holds an opportunity cost, and any output after this intersection is losing money.