For competing projects, net present value is preferred to internal rate of return because
  a.  maximizing IRR may not maximize the wealth of the owners.
  b.  in the final analysis, total dollars earned, not relative profitability, are what count.
  c.  choosing the project with the largest NPV maximizes the wealth of the shareholders.
  d.  assuming that cash flows are reinvested at the required rate of return is more realistic than assuming that cash flows are reinvested at the computed IRR.
  e.  of all of the above.