Which of the following statements is most correct?

a) If a project's internal rate of return (IRR) exceeds the required return, then the project's net present value (NPV) must be negative

b) The IRR calculation implicity assumes that all cash flows are reinvested at a rate of return equal to the IRR

c) If Project A has a higher IRR than Project B, then Project A must also have a higher NPV

d) A project with a NPV=0 is not acceptable