Apex domains cannot have CNAME records.
Question and response
Question
dig pcextreme.nl. NS
Answer
pcextreme.nl. 5 NS ns083.auroradns.info.
pcextreme.nl. 5 NS ns081.auroradns.eu.
pcextreme.nl. 5 NS ns082.auroradns.nl.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0