Apex domains cannot have CNAME records.
Question and response
Question
dig guc-inc.com. NS
Answer
guc-inc.com. 4 NS ns-1257.awsdns-29.org.
guc-inc.com. 4 NS ns-409.awsdns-51.com.
guc-inc.com. 4 NS ns-1596.awsdns-07.co.uk.
guc-inc.com. 4 NS ns-1307.awsdns-35.org.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0