Which of the following statements is correct? I. If the project has cash flows that change directions more than once over time (i.e. outflow, inflow, outflow...), there may be more than one possible value for internal rate of return (IRR), profitability index and payback period. In this situation, we should rely on the net present value (NPV) rule. II. When NPV is negative, IRR is not always smaller than the required rate of return (the discount rate). III. In mutually exclusive projects, we should always choose the one with the higher IRR. IV. An investigation of the degree to which NPV depends on assumptions made about several critical variables is called a scenario analysis. a. I and III only b. I and IV only c. II and IV only d. I, III and IV only e. None of the other answers are correct