【单选题】

TheBorder Gateway ProtocolBGP) is an interautonomous system (71) protocol. The primary function of aBGP speaking system is to exchange network (72) information with otherBGP system. This network reachability information includes information on the list ofAutonomous SystemASs) that reachability information traverses.BGP-4 provides a new set of mechanisms for Supporting (73) interdomain routing. These mechanisms include support for advertising an IP (74) and eliminate the concept of network class withinBGP.BGP-4 also introduces mechanisms that allow aggregation of routes, including (75) ofAS paths. These changes provide support for the proposed supernettting scheme.

A．answerless
B．connectionless
C．confirmless
D．classless