Apex domains cannot have CNAME records.
Question and response
Question
dig dsl4u.ca. NS
Answer
dsl4u.ca. 5 NS auth02.dns.acceleratedconnections.com.
dsl4u.ca. 5 NS auth01.dns.acceleratedconnections.com.
Authority
The response has no authority records.
Additional
auth01.dns.acceleratedconnections.com. 5 A 208.113.63.7
auth02.dns.acceleratedconnections.com. 5 A 208.113.63.39
auth01.dns.acceleratedconnections.com. 5 AAAA 2606:6200:1:0:0:0:0:2
auth02.dns.acceleratedconnections.com. 5 AAAA 2606:6200:1:1:0:0:0:2
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0