Youareconductingacdp-baseddiscoveryusinganedgeswitchfortheseed.thereisarouterbetweentheswitchandthewlse.noneoftheaccesspointsarediscovered，andthediscoverylogshowstheswitchissnmpunreachable.Whatistheproblem？（）
A.thesnmpcommunitiesontheswitchdonotmatchthewlse.
B.thesnmpcommunitiesontheaccesspointsdonotmatchthewlse.
C.thesnmpcommunitiesontheaccesspointsdonotmatchtheswitch.
D.thesnmpcommunitiesontherouterdonotmatchthewlse.