Final answer:
A profit-maximizing entrepreneur will shut down in the short run if the market price is below the minimum average variable cost.
Step-by-step explanation:
According to the standard model of pure competition, a profit-maximizing entrepreneur will shut down in the short run if the market price is below the minimum average variable cost. The intersection of the average variable cost curve and the marginal cost curve is called the shutdown point. If the market price is below this point, the firm is not even covering its variable costs, and staying open would make the losses larger. Therefore, the answer to your question is option A: Marginal cost > Average revenue.