While Monitoring Your Network with Orion NPM, You Notice That

While monitoring your network with Orion NPM, you notice that several of the devices in your remote offices periodically go into a "warning" state, but then quickly go back into an "up" state. While the devices are in "warning" state, the users at those sites report normal operations. What is the most likely cause of this occurrence?

A) Orion NPM is configured to poll too frequently.
B) During network congestion, ICMP packets are being dropped.
C) Orion NPM is not configured to poll frequently enough.
D) Firewall rules are periodically blocking ICMP packets.