Apex domains cannot have CNAME records.
Question and response
Question
dig o2sdns.fr. NS
Answer
o2sdns.fr. 4 NS nsc.bookmyname.com.
o2sdns.fr. 4 NS nsb.bookmyname.com.
o2sdns.fr. 4 NS nsa.bookmyname.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0