Which scenario best describes the difference between a monopolist and a competitive firm?
A monopolist chooses output where marginal revenue equals marginal cost
A competitive firm's short-run profit is always zero; a monopolist might have a positive short-
run profit.
A competitive firm cannot choose its level of output; a monopolist chooses its level of output.
A competitive firm sets price equal to marginal revenue; a monopolist sets price equal to
marginal cost.
A competitive firm's marginal-revenue curve is horizontal