Apex domains cannot have CNAME records.
Question and response
Question
dig sterlinginfosystems.com. NS
Answer
sterlinginfosystems.com. 5 NS ns-2028.awsdns-61.co.uk.
sterlinginfosystems.com. 5 NS ns-1015.awsdns-62.net.
sterlinginfosystems.com. 5 NS ns-131.awsdns-16.com.
sterlinginfosystems.com. 5 NS ns-1435.awsdns-51.org.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0