Aswitchthatistobeaddedtotheproductionnetworkhasbeenpreconfigured（trunks，VLANs，VTP，andSTP）andwastestedinyourlab.Afterinstallingtheswitchintothenetwork，theentirenetworkwentdown.Whatmightexplainwhathappened？（）

A.ThenewswitchhappenedtoberunningCiscoCatalystoperatingsystem，whiletheothernetworkswitcheswererunningCiscoIOSSoftware. B.TheconfigurationrevisionofthenewswitchwashigherthantheconfigurationrevisionoftheproductionVTPdomain. C.Thelinkcostsonthenewswitcharesettoahighvalue，causingallportsonthenewswitchtogointoaforwardingmodeandnoneintoblockingmode，therebycausingaspanning-treeloop. D.Theportsconnectingtothetwoswitcheshavebeenconfiguredincorrectly.Onesidehasthecommandswitchportmodeaccessandtheotherswitchportmodetrunk.