Which three of the following steps should be taken to troubleshoot a ‘test failed’ result...

Comprehensive and Detailed Explanation From Exact Extract:

A. Ensuring that firewall rules allow SNMP traffic is essential, especially when monitoring remote site nodes.

C. Basic connectivity should be checked by pinging the node from the SolarWinds application server.

D. If the SNMP community string is changed, the SNMP service on the device must be restarted for the new configuration to take effect.

Option B is not required unless SNMPv3 is specifically being used, and even then, SNMPv2c and SNMPv1 are still widely supported and commonly used.