WhichthreefeaturesarebenefitsofusingGREtunnelsinconjunctionwithIPsecforbuildingsite－to－siteVPNs?()

A.allowsdynamicroutingoverthetunnel

B.supportsmulti-protocol（non-IP）trafficoverthetunnel

C.reducesIPsecheadersoverheadsincetunnelmodeisused

D.simplifiestheACLusedinthecryptomap

E.usesVirtualTunnelInterface（VTI）tosimplifytheIPsecVPNconfiguration