All of the following statements regarding profit margin is true except

A、Profitmarginreflectsthepercentofprofitineachdollarofrevenue.;
B、Profitmarginisalsocalledreturnonsales.;
C、Profitmargincanbeusedtocompareafirm'sperformancetoitscompetitors.;
D、Profitmarginiscalculatedbydividingnetincomebynetsales.;
E、Profitmarginisnotausefulmeasureofacompany’soperatingresults.