A.ItaddstheVPNlabelintothetoplabelintheMPLSlabelstack
B.ItreplacesthetoplabelintheMPLSlabelstackwithaVPNlabelandpropagates
C.ItreplacesthebottomlabelintheMPLSlabelstackwithaVPNlabelandpropagates
D.ItremovesthetoplabelintheMPLSlabelstackanddoesaLayer3lookuponunderlyingIPpackets
E.Noneofabove
正确答案：参考D
