单选题 The presence of which of the following is mostly likely to result in the overproduction of the efficient quantity of goods of services in a market economy?

A、

A. Perfect competition.
B、

B. Taxes on sales.
C、

C. Monopoly.

【正确答案】 C

【答案解析】A decrease in the price of a substitute resource would induce producers to use the substitute resource, reducing demand for the resource in question. An increase in the price of a complementary resource would decrease demand for both resources.