Apex domains cannot have CNAME records.
Question and response
Question
dig thorcom.net. NS
Answer
thorcom.net. 5 NS ns0.thorcom.net.
thorcom.net. 5 NS ns1.bt.net.
thorcom.net. 5 NS ns1.thorcom.net.
thorcom.net. 5 NS ns2.thorcom.net.
Authority
The response has no authority records.
Additional
ns0.thorcom.net. 5 A 195.171.43.10
ns1.bt.net. 5 A 217.32.105.91
ns1.thorcom.net. 5 A 195.171.43.12
ns2.thorcom.net. 5 A 77.95.181.62
ns0.thorcom.net. 5 AAAA 2a00:2381:19c6:0:0:0:0:100
ns1.thorcom.net. 5 AAAA 2a00:2381:19c6:0:0:0:0:200
ns2.thorcom.net. 5 AAAA 2a01:5e40:102a:0:0:0:0:6200
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0