单项选择题

Youcreate200newuseraccounts.Theusersarelocatedinsixdifferentsites.Newusersreportthattheyreceivethefollowingerrormessagewhentheytrytologon:'Theusernameorpasswordisincorrect.'YouconfirmthattheuseraccountsexistandareenableD.Youalsoconfirmthattheusernameandpasswordinformationsuppliedarecorrect.YouneedtoidentifythecauseofthefailurE.YoualsoneedtoensurethatthenewusersareabletologonWhichutilityshouldyourun()