单选题 With respect to regulating a natural monopoly, which of the following pricing rules to regulate the natural monopoly firm will most likely require the government to provide a subsidy sufficient to compensate the firm in order to avoid the firm to leave the market?
A. Average cost pricing.
B. Marginal cost pricing.
C. Profit maximizing pricing.

【正确答案】 B
【答案解析】[解析] 如果政府对垄断者进行平均价格监管，企业将没有任何的超额利润，只能获得正常利润，如果政府对垄断者进行边际成本定价监管，可能使得产品价格低于企业的平均总成本，从而会使企业发生经济亏损，这时政府为了避免企业离开这个行业，会进行补贴或者允许企业进行差异化的定价，从而避免该企业离开这个市场。