WhydolargeOSPFnetworksuseahierarchicaldesign？（）

A.toconfinenetworkinstabilitytosingleareasofthenetwork.
B.toreducethecomplexityofrouterconfiguration.
C.tospeedupconvergence.
D.tolowercostsbyreplacingrouterswithdistributionlayerswitches.
E.todecreaselatencybyincreasingbandwidth.
F.toreduceroutingoverhead.

【参考答案】

A, C, F