Apex domains cannot have CNAME records.
Question and response
Question
dig videotron.net. NS
Answer
videotron.net. 5 NS dns5.videotron.net.
videotron.net. 5 NS dns1.videotron.net.
videotron.net. 5 NS dns2.videotron.net.
Authority
The response has no authority records.
Additional
dns1.videotron.net. 5 A 24.200.0.4
dns2.videotron.net. 5 A 96.22.246.146
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0