Apex domains cannot have CNAME records.
Question and response
Question
dig bdc.lt. NS
Answer
bdc.lt. 5 NS ns1.telecom.lt.
bdc.lt. 5 NS ns2.telecom.lt.
bdc.lt. 5 NS ns1.teo.lt.
bdc.lt. 5 NS ns2.teo.lt.
Authority
The response has no authority records.
Additional
ns1.telecom.lt. 5 A 212.59.0.1
ns2.telecom.lt. 5 A 212.59.0.2
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0