At an output quantity equal to 250, a mono
题型：单项选择题
问题：
At an output quantity equal to 250, a monopoly firm faces a demand curve with a price (P) of $50, a marginal cost (MC) and marginal revenue (MR) equal to $10, and an average total cost (ATC) equal to $12. The economic profit for this monopoly firm is closest to:（）
A. $12500.
B. $10000.
C. $9500.