Apex domains cannot have CNAME records.
Question and response
Question
dig orlen.pl. NS
Answer
orlen.pl. 5 NS dns1.orlen.pl.
orlen.pl. 5 NS dns2.orlen.pl.
orlen.pl. 5 NS dns3.orlen.pl.
Authority
The response has no authority records.
Additional
dns1.orlen.pl. 5 A 91.212.223.21
dns2.orlen.pl. 5 A 91.212.223.22
dns3.orlen.pl. 5 A 194.1.196.23
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0