Apex domains cannot have CNAME records.
Question and response
Question
dig nic.sh. NS
Answer
nic.sh. 5 NS c0.nic.sh.
nic.sh. 5 NS a0.nic.sh.
nic.sh. 5 NS a2.nic.sh.
nic.sh. 5 NS b0.nic.sh.
Authority
The response has no authority records.
Additional
a0.nic.sh. 78080 A 65.22.160.9
a2.nic.sh. 42147 A 65.22.163.9
b0.nic.sh. 132 A 65.22.161.9
c0.nic.sh. 6135 A 65.22.162.9
a0.nic.sh. 78080 AAAA 2a01:8840:9e:0:0:0:0:9
a2.nic.sh. 42147 AAAA 2a01:8840:a1:0:0:0:0:9
b0.nic.sh. 132 AAAA 2a01:8840:9f:0:0:0:0:9
c0.nic.sh. 6135 AAAA 2a01:8840:a0:0:0:0:0:9
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0