Which of the following statements regarding WACC is correct? I. If the project's risk is greater than the average risk of the firm, using the WACC will underestimate the present value of the project. II. If the project's risk differs from the average risk of the firm, the correct approach is to calculate the WACC of other firms operating in the same line of business as the new project. III. If the project has lower risk than the average risk for the firm, using WACC to discount cash flows will underestimate the present value of the project