Apex domains cannot have CNAME records.
Question and response
Question
dig vjm.dk. NS
Answer
vjm.dk. 5 NS ns2.123hotel.dk.
vjm.dk. 5 NS ns1.123hotel.dk.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0