SNMP agents collect information on network resources and events. In which type of network equipment can you use SNMP agents?

A.
Servers

B.
Routers

C.
Hubs

D.
All of the above.

Explanation:
You can use SNMP agents in a variety of network equipment, of which servers, routers and hubs are a few.
References:
Charles J. Brooks, Server+ Certification Exam Cram 2 (Exam SK0-002), QUE Publishing, Indianapolis, 2006, pp. 424-427.