Compared to a monopoly, a perfectly competitive market tends to produce (b) more output and charge a lower price. In perfectly-competitive markets, the strong competition guides the market to equilibrium. With a monopoly, on the other hand, the firm has the ability to maximize profits and will produce at the (lower) output level where marginal cost equals marginal revenue. They will then set the (higher) price such that the quantity demanded at that price equals the profit-maximizing output level.