Apex domains cannot have CNAME records.
Question and response
Question
dig nic.cr. NS
Answer
nic.cr. 5 NS p.nic.cr.
nic.cr. 5 NS a.lactld.org.
nic.cr. 5 NS dns.nic.cr.
nic.cr. 5 NS ca2.nic.cr.
nic.cr. 5 NS de.nic.cr.
nic.cr. 5 NS ca1.nic.cr.
Authority
The response has no authority records.
Additional
a.lactld.org. 4 A 200.0.68.10
p.nic.cr. 147035 A 204.61.216.89
de.nic.cr. 10707 A 194.0.11.107
ca1.nic.cr. 116570 A 185.159.197.100
ca2.nic.cr. 59374 A 185.159.198.100
dns.nic.cr. 119981 A 200.107.82.100
a.lactld.org. 4 AAAA 2801:14:a000:0:0:0:0:10
p.nic.cr. 147035 AAAA 2001:500:14:6089:ad:0:0:1
de.nic.cr. 10707 AAAA 2001:678:e:107:0:0:0:53
ca1.nic.cr. 116570 AAAA 2620:10a:80aa:0:0:0:0:100
ca2.nic.cr. 59374 AAAA 2620:10a:80ab:0:0:0:0:100
dns.nic.cr. 119981 AAAA 2001:13c7:7004:1:0:0:0:d100
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0