Apex domains cannot have CNAME records.
Question and response
Question
dig trustico.com. NS
Answer
trustico.com. 5 NS c.ns.trustico.com.
trustico.com. 5 NS d.ns.trustico.com.
trustico.com. 5 NS e.ns.trustico.com.
trustico.com. 5 NS f.ns.trustico.com.
trustico.com. 5 NS a.ns.trustico.com.
trustico.com. 5 NS b.ns.trustico.com.
Authority
The response has no authority records.
Additional
a.ns.trustico.com. 5 A 96.45.80.1
b.ns.trustico.com. 5 A 46.31.236.1
c.ns.trustico.com. 5 A 43.247.170.1
d.ns.trustico.com. 5 A 96.45.81.1
e.ns.trustico.com. 5 A 46.31.237.1
f.ns.trustico.com. 5 A 43.247.171.1
a.ns.trustico.com. 5 AAAA 2600:180a:1001:0:0:0:0:1
b.ns.trustico.com. 5 AAAA 2600:180b:2001:0:0:0:0:1
c.ns.trustico.com. 5 AAAA 2600:180c:3001:0:0:0:0:1
d.ns.trustico.com. 5 AAAA 2600:180a:4001:0:0:0:0:1
e.ns.trustico.com. 5 AAAA 2600:180b:5001:0:0:0:0:1
f.ns.trustico.com. 5 AAAA 2600:180c:6001:0:0:0:0:1
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0