Apex domains cannot have CNAME records.
Question and response
Question
dig hsia.telus.net. NS
Answer
hsia.telus.net. 5 NS dns21.telus.ca.
hsia.telus.net. 5 NS dns21.telus.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0