Apex domains cannot have CNAME records.
Question and response
Question
dig exactonline.nl. NS
Answer
exactonline.nl. 4 NS ns-178.awsdns-22.com.
exactonline.nl. 4 NS ns-1268.awsdns-30.org.
exactonline.nl. 4 NS ns-537.awsdns-03.net.
exactonline.nl. 4 NS ns-1938.awsdns-50.co.uk.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0