Apex domains cannot have CNAME records.
Question and response
Question
dig adicking.com. NS
Answer
adicking.com. 4 NS ns-1406.awsdns-47.org.
adicking.com. 4 NS ns-946.awsdns-54.net.
adicking.com. 4 NS ns-1000.awsdns-61.net.
adicking.com. 4 NS ns-1721.awsdns-23.co.uk.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0