Apex domains cannot have CNAME records.
Question and response
Question
dig nic.GDN. NS
Answer
nic.GDN. 1 NS ns1.nic.GDN.
nic.GDN. 1 NS ns3.nic.GDN.
Authority
The response has no authority records.
Additional
ns1.nic.gdn. 95839 A 194.0.25.18
ns3.nic.gdn. 144078 A 194.0.26.11
ns1.nic.gdn. 95839 AAAA 2001:678:20:0:0:0:0:18
ns3.nic.gdn. 144078 AAAA 2001:67c:10e0:0:0:0:0:11
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0