Apex domains cannot have CNAME records.
Question and response
Question
dig nic.ua. NS
Answer
nic.ua. 5 NS ns1.uadns.com.
nic.ua. 5 NS ns2.uadns.com.
Authority
The response has no authority records.
Additional
ns1.uadns.com. 5 A 178.62.201.147
ns2.uadns.com. 5 A 157.90.171.155
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0