Apex domains cannot have CNAME records.
Question and response
Question
dig simkin.ca. NS
Answer
simkin.ca. 5 NS ns-973.awsdns-57.net.
simkin.ca. 5 NS ns-285.awsdns-35.com.
simkin.ca. 5 NS ns-1728.awsdns-24.co.uk.
simkin.ca. 5 NS ns-1109.awsdns-10.org.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0