One of the key differences between the decisions to add labor or capital to the production process is that the returns to labor:（）
A. are relatively immediate, but those to capital may be years into the future so they must be evaluated as future values.
B. must be projected into the future and evaluated as present values, while returns to capital can be evaluated immediately based upon market interest rates.
C. are relatively immediate, but those to capital may be years into the future so they must be evaluated as present values.
参考答案：C
解析：
The returns to labor are relatively immediate, and can he compared with the overall wage cost of the labor. The returns from the addition of capital occur over a p of years, so must be discounted back to today and evaluated as present values versus the cost of the capital.