Apex domains cannot have CNAME records.
Question and response
Question
dig lt. NS
Answer
lt. 5 NS e.tld.lt.
lt. 5 NS d.tld.lt.
lt. 5 NS a.tld.lt.
lt. 5 NS c.tld.lt.
lt. 5 NS b.tld.lt.
lt. 5 NS f.tld.lt.
Authority
The response has no authority records.
Additional
a.tld.lt. 164298 A 185.150.40.131
b.tld.lt. 164298 A 194.0.20.1
c.tld.lt. 164298 A 194.0.1.4
d.tld.lt. 164298 A 194.0.3.1
e.tld.lt. 164298 A 194.0.18.1
f.tld.lt. 164298 A 194.0.19.1
b.tld.lt. 164298 AAAA 2001:678:19:0:0:0:0:1
c.tld.lt. 164298 AAAA 2001:678:4:0:0:0:0:4
d.tld.lt. 164298 AAAA 2001:678:6:0:0:0:0:1
f.tld.lt. 164298 AAAA 2001:678:8c:0:0:0:0:1
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0