Apex domains cannot have CNAME records.
Question and response
Question
dig time.nl. NS
Answer
time.nl. 5 NS ns2.sidnlabs.nl.
time.nl. 5 NS ns5.sidn.nl.
time.nl. 5 NS ns1.sidnlabs.nl.
Authority
The response has no authority records.
Additional
ns1.sidnlabs.nl. 5 A 94.198.159.8
ns2.sidnlabs.nl. 5 A 194.0.28.11
ns5.sidn.nl. 5 A 147.75.205.55
ns1.sidnlabs.nl. 5 AAAA 2a00:d78:0:712:94:198:159:8
ns2.sidnlabs.nl. 5 AAAA 2001:678:2c:0:194:0:28:11
ns5.sidn.nl. 5 AAAA 2604:1380:4601:5c00:0:0:0:d
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0