Apex domains cannot have CNAME records.
Question and response
Question
dig videotron.ca. NS
Answer
videotron.ca. 4 NS dnsb.videotron.ca.
videotron.ca. 4 NS dnsa.videotron.ca.
videotron.ca. 4 NS dnsc.videotron.ca.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0