Average accounting return Internal rate of return Net present value. O Payback period Profitability index Question 2 9 The discount rate that makes the net present value of an investment exactly equal to zero is the: Internal rate of return. O Prontability Index. Payback period O Average accounting return. Discounted payback period. Question 3 9 The difference between the market value of an investment and its cost is its: Profitability index. Discounted payback period