Apex domains cannot have CNAME records.
Question and response
Question
dig quaventro.com. NS
Answer
quaventro.com. 5 NS ns-559.awsdns-05.net.
quaventro.com. 5 NS ns-955.awsdns-55.net.
quaventro.com. 5 NS ns-1404.awsdns-47.org.
quaventro.com. 5 NS ns-1566.awsdns-03.co.uk.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0