Apex domains cannot have CNAME records.
Question and response
Question
dig fr.clara.net. NS
Answer
fr.clara.net. 5 NS ns4.fr.clara.net.
fr.clara.net. 5 NS ns3.fr.clara.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0