The law of diminishing returns states that for a given production process, as more and more of a resource (such as labor) are added, holding the quantities of other resources fixed:（）

单项选择题Which of the following statements regarding diminishing marginal returns is most accurate（）

A. As the quantity produced rises, costs begin to rise at a decreasing rate.
B. As the quantity produced falls, costs begin to rise at a decreasing rate.
C. As the quantity produced rises, costs begin to rise at an increasing rate.

单项选择题Accounting profit is often an unsatisfactory performance measure from an economic point of view because it:（）

A. does not consider depreciation.
B. does not consider the opportunity costs of equity capital.
C. considers marginal costs rather than average costs.