Apex domains cannot have CNAME records.
Question and response
Question
dig 8.d-53.info. NS
Answer
8.d-53.info. 5 NS ns.iij-dns.net.
8.d-53.info. 5 NS ns.iij-dns.jp.
8.d-53.info. 5 NS ns.iij-dns.biz.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0