单项选择题 InBGProuting，whatdoestheruleofsynchronizationmean？（）

单项选择题 YouhavearouterrunningBGPfortheMPLSnetworkandOSPFforthelocalLANnetworkatthesalesoffice.ArouteisbeinglearnedfromtheMPLSnetworkthatalsoexistsontheOSPFlocalnetwork.ItisimportantthattherouterchoosesthelocalLANroutebeinglearnedfromthedownstreamswitchrunningOSPFratherthantheupstreamBGPneighbor.Also，ifthelocalOSPFroutegoesaway，theBGProuteneedstobeused.WhatshouldbeconfiguredtomakesurethattherouterwillchoosetheLANnetworkasthepreferredpath？（）

问答题 BGP的Community对于选择最优路径有什么作用？