We pick i.root-servers.net, one of the 13 root servers (1), and ask it about 7.9.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.e.0.0.c.7.6.0.1.0.0.2.ip6.arpa and learn that ip6.arpa is delegated to six name servers (2), so we ask b.ip6-servers.arpa and get the following answer:
Authoritative answer
ANSWER for 7.9.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.e.0.0.c.7.6.0.1.0.0.2.ip6.arpa.