4. Sunk costs a. should always be included as part of a project's cost b. should never be included as part of a project's cost. c. should he included only when a project has normal cash flows d be included when the IRR is less than the cost of capital. 5. The IRR is: that makes the NPV positive. b. the discount rate that makes the NPV negative and the profitability index greater than one c. the discount rate that equates the present value of the cash inflows with the cost of the project d. the rate of return that makes the NPV positive. 6. "Normal" cash flows: a. begin negative, then become and stay positive. b. begin positive, then become and stay negative. c. begin positive, then alternate each period d. begin negative, then alternate each period