Apex domains cannot have CNAME records.
Question and response
Question
dig static.inetia.pl. NS
Answer
static.inetia.pl. 2 NS pds3.inetia.pl.
static.inetia.pl. 2 NS pds1.inetia.pl.
static.inetia.pl. 2 NS pds2.inetia.pl.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0