Apex domains cannot have CNAME records.
Question and response
Question
dig rotld.Ro. NS
Answer
rotld.Ro. 5 NS ns-a.rnc.Ro.
rotld.Ro. 5 NS ns.rnc.Ro.
Authority
The response has no authority records.
Additional
ns.rnc.ro. 5 A 192.162.16.21
ns-a.rnc.ro. 5 A 192.162.16.31
ns.rnc.ro. 5 AAAA 2a03:5e80:0:4:192:162:16:21
ns-a.rnc.ro. 5 AAAA 2a03:5e80:0:4:192:162:16:31
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0