单选题 ff the marginal benefit of the last unit of a good or service consumed was $25, the marginal benefit of the next unit consumed is most likely to be:

A. $25.
B. $24.
C. $26.

【正确答案】 B

【答案解析】In most cases, the marginal benefit of a good or service decreases as the quantity consumed increases. So, $24 is the most likely answer. This principle is called decreasing marginal benefit.