Chuckrox8

is this the question related to the options? feeling lazy to pick up the book and check, right now.
If so, on the basis on the pre-option NPV - you have to do it based on the probability weighted after-tax cash flows. But for the “option” part - you realize that it will be realized (or become feasible) only when the higher cash flow is available. Otherwise, you would not choose to exercise the option.