Apex domains cannot have CNAME records.
Question and response
Question
dig mameromsquestions.org. NS
Answer
mameromsquestions.org. 5 NS ns-1129.awsdns-13.org.
mameromsquestions.org. 5 NS ns-310.awsdns-38.com.
mameromsquestions.org. 5 NS ns-135.awsdns-16.com.
mameromsquestions.org. 5 NS ns-850.awsdns-42.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0