Apex domains cannot have CNAME records.
Question and response
Question
dig kki.pl. NS
Answer
kki.pl. 5 NS ns.kkibci.pl.
kki.pl. 5 NS ns2.kkibci.pl.
Authority
The response has no authority records.
Additional
ns.kkibci.pl. 5 A 81.21.192.130
ns2.kkibci.pl. 5 A 81.21.201.2
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0