Project X has an internal rate of return of 20 percent. Project Y has an internal rate of return of 15 percent. Both projects have a positive net present value. Which of the following statements is most correct?( )

A、Project X must have a higher net present value than Project Y.
B、If the two projects have the same WACC, Project X must have a higher net present value.
C、Project X must have a shorter payback than Project Y.
D、Statements b and c are correct.
E、None of the statements above is correct.