Which of the following statements related to the internal rate of return (IRR) are correct? I. The IRR method of analysis can be adapted to handle non-conventional cash flows. II. The IRR that causes the net present value of the differences between two project's cash flows to equal zero is called the crossover rate. III. If the IRR tends to be used more than net present value simply because its results are easier to comprehend. IV. Both the timing and the amount of a project's cash flows affect the value of the project's IRR.