Which of the following statements is correct?

	a.	The higher the WACC, the shorter the discounted payback period.
	b.	The MIRR and NPV decision criteria can never conflict.
	c.	The IRR method can never be subject to the multiple IRR problem, while the MIRR method can be.
	d.	One reason some people prefer the MIRR to the regular IRR is that the MIRR is based on what is generally a more reasonable assumption about the reinvestment rate than the regular IRR.