Which of the following statements describes the purpose of ndpmon?

A.
It monitors the network for neighbor discovery messages from new IPv6 hosts and routers.

B.
It monitors remote hosts by periodically sending echo requests to them.

C.
It monitors the availability of a network link by querying network interfaces.

D.
It monitors the network for IPv4 nodes that have not yet migrated to IPv6.

E.
It monitors log files for failed login attempts in order to block traffic from offending network nodes.

Explanation:
https://en.wikipedia.org/wiki/NDPMon