Apex domains cannot have CNAME records.
Question and response
Question
dig afnic.fr. NS
Answer
afnic.fr. 5 NS g.ext.nic.fr.
afnic.fr. 5 NS ns1.nic.fr.
afnic.fr. 5 NS ns2.nic.fr.
afnic.fr. 5 NS ns3.nic.fr.
Authority
The response has no authority records.
Additional
g.ext.nic.fr. 103986 A 194.0.36.1
g.ext.nic.fr. 103986 AAAA 2001:678:4c:0:0:0:0:1
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0