Apex domains cannot have CNAME records.
Question and response
Question
dig marisamarconi.com. NS
Answer
marisamarconi.com. 5 NS ns-1216.awsdns-24.org.
marisamarconi.com. 5 NS ns-1857.awsdns-40.co.uk.
marisamarconi.com. 5 NS ns-1168.awsdns-18.org.
marisamarconi.com. 5 NS ns-1839.awsdns-37.co.uk.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0