Apex domains cannot have CNAME records.
Question and response
Question
dig whih.nl. NS
Answer
whih.nl. 3 NS ns2.whih.nl.
whih.nl. 3 NS ns3.whih.nl.
whih.nl. 3 NS ns1.whih.nl.
Authority
The response has no authority records.
Additional
ns1.whih.nl. 3 A 5.61.248.164
ns2.whih.nl. 3 A 93.119.13.218
ns3.whih.nl. 3 A 136.144.249.197
ns1.whih.nl. 3 AAAA 2a01:7860:0:0:db:1152:a:1
ns2.whih.nl. 3 AAAA 2a01:7c8:bb09:15e:5054:ff:fed2:6901
ns3.whih.nl. 3 AAAA 2a01:7c8:d007:3a2:5054:ff:fe68:e003
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0