问题
单项选择题
The minimum supply price, the lowest price at which a producer is willing to supply an additional unit of a good, is:（）
A. less than the marginal revenue for the additional unit.
B. the price at which producer surplus is maximized.
C. the marginal cost of producing the additional unit.
答案
参考答案：C
解析：
The minimum supply price that producers must receive if they are to produce an additional unit of output is the opportunity cost of producing that unit, i.e. the marginal cost. The marginal cost curve is the short-run supply curve for the good.