Apex domains cannot have CNAME records.
Question and response
Question
dig bank. NS
Answer
bank. 5 NS d.nic.bank.
bank. 5 NS y.nic.bank.
bank. 5 NS x.nic.bank.
bank. 5 NS w.nic.bank.
bank. 5 NS f.nic.bank.
bank. 5 NS e.nic.bank.
Authority
The response has no authority records.
Additional
d.nic.bank. 11154 A 156.154.103.27
e.nic.bank. 11154 A 156.154.104.27
f.nic.bank. 11154 A 156.154.105.27
w.nic.bank. 11154 A 37.209.192.10
x.nic.bank. 11154 A 37.209.194.10
y.nic.bank. 11154 A 37.209.196.10
d.nic.bank. 11154 AAAA 2610:a1:1010:0:0:0:0:27
e.nic.bank. 11154 AAAA 2610:a1:1011:0:0:0:0:27
f.nic.bank. 11154 AAAA 2610:a1:1012:0:0:0:0:27
w.nic.bank. 11154 AAAA 2001:dcd:1:0:0:0:0:10
x.nic.bank. 11154 AAAA 2001:dcd:2:0:0:0:0:10
y.nic.bank. 11154 AAAA 2001:dcd:3:0:0:0:0:10
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0