Apex domains cannot have CNAME records.
Question and response
Question
dig spiceworks.com. NS
Answer
spiceworks.com. 5 NS ns-518.awsdns-00.net.
spiceworks.com. 5 NS ns-1720.awsdns-23.co.uk.
spiceworks.com. 5 NS ns-198.awsdns-24.com.
spiceworks.com. 5 NS ns-1051.awsdns-03.org.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0