Which of the following net present value (NPV) and internal rate of return (IRR) statement is correct? (a) If a project's IRR is equal the discount rate, the project's NPV must be greater than zero. (b) A project's NPV will always be greater than zero if project's IRR is greater than zero (c) An investment should be accepted if the NPV is positive. (d) An investment with greater cash inflows than cash outflows, regardless of when the cash flows occur, will always have a positive NPV