Which concepts regarding NPV, IRR, payback period, discounted payback period, profitability index is true? a) When a project generating non-conventional cash flow, we can use either NPV or IRR to determine if the project is appropriate for the company b) The payback period considers time value of money whereas discounted payback period does not consider time value of money c) Profitability index does not take initial cash outflow into consideration d) If we plot the discount rate on the X-axis and NPV on the y-axis, the y-intercept shows the IRR rate e) The NPV is always preferable regarding the project is generating conventional or unconventional cash flow