Which of the following is NOT a valid method of modifying cash flows to produce a MIRR?
A: Discount all of the negative cash flows to time 0 and leave the positive cash flows alone.
B: Leave the initial cash flow alone and compound all of the remaining cash flows to the final period of the project.
C: Discount all of the negative cash flows to the present and compound all of the positive cash flows to the end of the project.
D: Turn multiple negative cash flows into a single negative cash flow by summing all negative cash flows over the project's lifetime.