Apex domains cannot have CNAME records.
Question and response
Question
dig hix.nl. NS
Answer
hix.nl. 5 NS ns-3.eu.
hix.nl. 5 NS ns2.hix.nl.
hix.nl. 5 NS ns1.hix.nl.
Authority
The response has no authority records.
Additional
ns1.hix.nl. 5 A 83.137.192.101
ns2.hix.nl. 5 A 31.3.110.75
ns-3.eu. 5 A 85.10.135.155
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0