Apex domains cannot have CNAME records.
Question and response
Question
dig netsolution.com.pl. NS
Answer
netsolution.com.pl. 3 NS ns1.netserwer24.pl.
netsolution.com.pl. 3 NS ns2.netserwer24.pl.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0