单项选择题
The Simple Network Management Protocol (SNMP)is an （） protocol that facilitates the exchange of management information between （） . It is part of the Transmission Control Protocol/Internet Protocol(TCP/IP) protocol suite. SNMP enables network （） to manage network performance, find and sole network problems, and plan for （） An SNMP -managed network consists of three key components: managed devices , （） ,and network -management systems .
（） ,and network -management systems .
A.administrators
B.agents
C.managers
D.servers