Apex domains cannot have CNAME records.
Question and response
Question
dig ks.ua. NS
Answer
ks.ua. 5 NS nss.kh.ua.
ks.ua. 5 NS nix.ns.ua.
ks.ua. 5 NS ns.dn.ua.
ks.ua. 5 NS ho1.ns.ks.ua.
Authority
The response has no authority records.
Additional
ho1.ns.ks.ua. 5 A 195.47.253.15
ho1.ns.ks.ua. 5 AAAA 2001:67c:258:0:0:0:0:15
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0