Apex domains cannot have CNAME records.
Question and response
Question
dig helpsystems.com. NS
Answer
helpsystems.com. 5 NS ns-283.awsdns-35.com.
helpsystems.com. 5 NS ns-1682.awsdns-18.co.uk.
helpsystems.com. 5 NS ns-1118.awsdns-11.org.
helpsystems.com. 5 NS ns-1017.awsdns-63.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0