Apex domains cannot have CNAME records.
Question and response
Question
dig ba. NS
Answer
ba. 5 NS lim.utic.net.ba.
ba. 5 NS bosna.utic.net.ba.
ba. 5 NS sava.utic.net.ba.
ba. 5 NS una.utic.net.ba.
Authority
The response has no authority records.
Additional
lim.utic.net.ba. 138262 A 194.0.25.38
una.utic.net.ba. 155170 A 204.61.216.117
sava.utic.net.ba. 172800 A 195.130.35.3
bosna.utic.net.ba. 172800 A 195.130.35.5
lim.utic.net.ba. 138262 AAAA 2001:678:20:0:0:0:0:38
una.utic.net.ba. 155170 AAAA 2001:500:14:6117:ad:0:0:1
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0