Apex domains cannot have CNAME records.
Question and response
Question
dig sgi-usa-florida.org. NS
Answer
sgi-usa-florida.org. 4 NS ns-367.awsdns-45.com.
sgi-usa-florida.org. 4 NS ns-173.awsdns-21.com.
sgi-usa-florida.org. 4 NS ns-1744.awsdns-26.co.uk.
sgi-usa-florida.org. 4 NS ns-377.awsdns-47.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0