Apex domains cannot have CNAME records.
Question and response
Question
dig DeltoServices.nl. NS
Answer
deltoservices.nl. 5 NS ns1.transip.nl.
deltoservices.nl. 5 NS ns.deltoservices.nl.
deltoservices.nl. 5 NS ns2.transip.eu.
Authority
The response has no authority records.
Additional
ns.DeltoServices.nl. 5 A 136.144.251.176
ns1.transip.nl. 5 A 195.8.195.195
ns2.transip.eu. 5 A 37.97.199.195
ns.DeltoServices.nl. 5 AAAA 2a01:7c8:d007:277:5054:ff:fe68:bbc9
ns1.transip.nl. 5 AAAA 2a01:7c8:7000:195:0:0:0:195
ns2.transip.eu. 5 AAAA 2a01:7c8:f:c1f:0:0:0:195
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0