SimpleNetworkManagementProtocol(SNMP)isanInternetStandardprotocolforcollectingandorganizinginformationaboutmanageddevicesonIPnetworksandformodifyingthatinformationtochangedevice().SNMPisacomponentoftheInternetProtocolSuiteasdefinedbytheInternet()TaskForce.SNMPoperatesinthe()layeroftheInternetprotocolsuite.AllSNMPmessagesaretransportedviaUser()Protocol.AnSNMP-managednetworkconsistsofthreekeycomponents:a)Manageddevices,b)(请作答此空)(i.e.，softwarewhichrunsonmanageddevices),andc)Networkmanagementstation(NMS)(i.e.，softwarewhichrunsonthemanager).
A.Agent
B.Client
C.Proxy
D.User
正确答案是A