问题
单项选择题
A firm should continue adding to its capital until the marginal product of capital is:（）
A. equal to the marginal revenue product of labor.
B. greater than the cost of capital.
C. equal to the cost of capital.
答案
参考答案：C
解析：
A firm should continue to accept capital projects until the marginal revenue product of capital (the value added) is equal to the cost of capital. Prior to this point, the firm gains from each unit of capital added.
