Final answer:
A pure monopolist seeks the output that will yield the greatest per-unit profit due to the monopoly's less elastic demand curve. The correct answer is D. Monopolistic competition.
Step-by-step explanation:
A pure monopolist seeks the output that will yield the greatest per-unit profit due to the monopoly's demand curve being less elastic compared to other competitive market structures.
In a perfect competition, the demand curve faced by a firm is perfectly elastic, meaning it can sell all the output it wishes at the prevailing market price. On the other hand, a monopoly faces the market demand curve, which is less elastic, and can only sell more output by decreasing the price it charges. As a result, the monopolist aims to maximize per-unit profit by finding the quantity where marginal revenue is equal to marginal cost.
Therefore, the correct answer is D. Monopolistic competition.