Apex domains cannot have CNAME records.
Question and response
Question
dig tower.ca. NS
Answer
tower.ca. 5 NS ns2.wizard.ca.
tower.ca. 5 NS ns.wizard.ca.
tower.ca. 5 NS ns3.wizard.ca.
Authority
The response has no authority records.
Additional
ns.wizard.ca. 5 A 104.128.145.1
ns2.wizard.ca. 5 A 104.128.145.65
ns3.wizard.ca. 5 A 65.39.244.13
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0