问题如下：
When assembling the cash flows to calculate an NPV or IRR, the project’s after-tax interest expenses should be subtracted from the cash flows for:
选项：
A. the IRR calculation, but not the NPV calculation.
B. both the NPV calculation and the IRR calculation.
C. neither the NPV calculation nor the IRR calculation.
解释：
C is correct.
Financing costs are not subtracted from the cash flows for either the NPV or the IRR. The effects of financing costs are captured in the discount rate used.
sunk cost 和interest cost 应该igonre. 分析现金流时不考虑利息费用的意思是说要把利息费用做“扣减”还是“不剔除”呢？
