Apex domains cannot have CNAME records.
Question and response
Question
dig erotrend.nl. NS
Answer
erotrend.nl. 5 NS ns1.ek-hosting.net.
erotrend.nl. 5 NS ns3.ek-hosting.nl.
erotrend.nl. 5 NS ns2.ek-hosting.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0