Apex domains cannot have CNAME records.
Question and response
Question
dig clearcable.ca. NS
Answer
clearcable.ca. 5 NS ns1.clearcable.ca.
clearcable.ca. 5 NS ns2.clearcable.ca.
clearcable.ca. 5 NS ns3.clearcable.ca.
Authority
The response has no authority records.
Additional
ns1.clearcable.ca. 5 A 192.160.255.43
ns2.clearcable.ca. 5 A 192.160.255.44
ns3.clearcable.ca. 5 A 24.53.80.18
ns1.clearcable.ca. 5 AAAA 2620:120:8000:cb:216:3eff:fe1c:fc0c
ns2.clearcable.ca. 5 AAAA 2620:120:8000:cb:216:3eff:fea6:68a7
ns3.clearcable.ca. 5 AAAA 2604:9380:0:c8:216:3eff:fe20:e903
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0