单选题 At a fixed level of capital, output increases as the quantity of labor increases, but at a decreasing rate. This phenomenon is an example of: A. law of diminishing costs to labor. B. law of diminishing returns to capital. C. law of diminishing returns to labor.

【正确答案】 C

【答案解析】The law of diminishing returns states that at some point, as more and more of a resource (e. g. , labor) is devoted to a production process, holding the quantity of other inputs constant, the output increases, but at a decreasing rate.