Apex domains cannot have CNAME records.
Question and response
Question
dig onlineresponse.net. NS
Answer
onlineresponse.net. 4 NS ns-1569.awsdns-04.co.uk.
onlineresponse.net. 4 NS ns-355.awsdns-44.com.
onlineresponse.net. 4 NS ns-665.awsdns-19.net.
onlineresponse.net. 4 NS ns-1954.awsdns-52.co.uk.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0