Which of the following statements is correct? assume that the project being considered has normal cash flows, with one outflow followed by a series of inflows. a) the higher the wacc used to calculate the npv, the lower the calculated npv will be. b) if a project's npv is greater than zero, then its irr must be less than the wacc. c) if a project's npv is greater than zero, then its irr must be less than zero. d) the npvs of relatively risky projects should be found using relatively low waccs.