The underlying cause of ranking conflicts between the net present value (NPV) and internal rate of return (IRR) methods is the underlying assumption related to the:

Your answer: B was incorrect. The correct answer was C) reinvestment rate.

The IRR method assumes all future cash flows can be reinvested at the IRR. This may not be feasible because the IRR is not based on market rates. The NPV method uses the weighted average cost of capital (WACC) as the appropriate discount rate.

那你为什么认为B是正确的呢？他们的time为什么不一样？

当我们用NPV的时候，我们会用到discount rate，通过计算会发现通常这个rate和IRR这个rate是不同的。

如果我们得到IRR后，我们通常会拿IRR和公司requirement rate of return做比较，然后做出选择。

不知是否解答了你的疑问。