Apex domains cannot have CNAME records.
Question and response
Question
dig ro. NS
Answer
ro. 5 NS primary.rotld.ro.
ro. 5 NS dns-ro.denic.de.
ro. 5 NS dns-c.rotld.ro.
ro. 5 NS dns-at.rotld.ro.
ro. 5 NS sec-dns-b.rotld.ro.
ro. 5 NS sec-dns-a.rotld.ro.
Authority
The response has no authority records.
Additional
dns-c.rotld.ro. 43821 A 194.0.11.113
dns-at.rotld.ro. 43821 A 78.104.145.6
primary.rotld.ro. 168061 A 192.162.16.18
sec-dns-a.rotld.ro. 43821 A 192.162.16.20
sec-dns-b.rotld.ro. 171293 A 193.230.31.230
dns-c.rotld.ro. 43821 AAAA 2001:678:e:113:0:0:0:53
dns-at.rotld.ro. 43821 AAAA 2001:628:453:bb:0:0:0:6
primary.rotld.ro. 168061 AAAA 2a03:5e80:0:4:192:162:16:18
sec-dns-a.rotld.ro. 43821 AAAA 2a03:5e80:0:4:192:162:16:20
sec-dns-b.rotld.ro. 171293 AAAA 2a03:5e80:0:5:193:230:31:230
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0