Networksecurityconsistsofpoliciesandpracticestopreventandmonitor()access,misuse,modification,ordenialofacomputernetworkandnetwork-accessibleresources.Networksecurityinvolvestheauthorizationofaccesstodatainanetwork,whichiscontrolledbythenetwork().UserschooseorareassignedanIDandpasswordorotherauthenticatinginformationthatallowsthemtoaccesstoinformationandprogramswithintheirauthority.Networksecuritysecuresthenetwork,aswellasprotectingandoverseeingoperationsbeingdone.Themostcommonandsimplewayofprotectinganetworkresourceisbyassigningita(请作答此空)nameandacorrespondingpassword.Networksecuritystartswithauthentication.Onceauthenticateda()enforcespoliciessuchaswhatservicesareallowedtobeaccessedbythenetworkusers.Thougheffectivetopreventunauthorizedaccess,thiscomponentmayfailtocheckpotentiallyharmfulcontentsuchascomputer()orTrojansbeingtransmittedoverthenetwork
A.complex
B.unique
C.catchy
D.long
正确答案是B