Which one of the following is the estimated rate (i.e., percentage) that makes the discounted present value of future after-tax cash inflows of a project equal to the initial investment outlay for the project?

A) Weighted-average cost of capital (WACC).

B) Payback period, in years.

C) Book (accounting) rate of return.

D) Internal rate of return (IRR).

E) Accounting rate of return (ARR), after tax.