WhataretwocharacteristicsofGSS?()

A.Ithelpsverifyend-to-endpathavailability.

B.Itprovidestrafficreroutingincaseofdisaster.

C.HSRP，GLBP，andVRRPcanbeclientsofGSS.

D.BGPmustbetheroutingprotocolbetweenthedistributeddatacenters.

E.DNSresponsivenessisimprovedbyprovidingcentralizeddomainmanagement.