Refertotheexhibit.WhatistheeffectonthetrustboundaryofconfiguringthecommandmlsqostrustcosontheswitchportthatisconnectedtotheIPphone？（）

<img src='https://img2.soutiyun.com/shangxueba/ask/64308001-64311000/64310716/0c71d5adff8c10241505b903d9762104.jpg' /> A．EffectivelythetrustboundaryhasbeenmovedtotheIPphone B．ThehostisnowestablishingtheCoSvalueandhaseffectivelybecomethetrustboundary C．TheswitchisrewritingpacketsitreceivesfromtheIPphoneanddeterminingtheCoSvalue D．TheswitchwillnolongertagincomingvoicepacketsandwilltrustthedistributionlayerswitchtosettheCoS E．RTPwillbeusedtonegotiateaCoSvaluebaseduponbandwidthutilizationonthelink