Apex domains cannot have CNAME records.
Question and response
Question
dig pluracol.com. NS
Answer
pluracol.com. 5 NS ns-231.awsdns-28.com.
pluracol.com. 5 NS ns-135.awsdns-16.com.
pluracol.com. 5 NS ns-2011.awsdns-59.co.uk.
pluracol.com. 5 NS ns-1392.awsdns-46.org.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0