Apex domains cannot have CNAME records.
Question and response
Question
dig dc.uz. NS
Answer
dc.uz. 4 NS rdns1.dc.uz.
dc.uz. 4 NS ns1.dc.uz.
Authority
The response has no authority records.
Additional
ns1.dc.uz. 4 A 91.212.89.4
rdns1.dc.uz. 4 A 91.212.89.2
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0