Apex domains cannot have CNAME records.
Question and response
Question
dig eftydns.com. NS
Answer
eftydns.com. 5 NS mallory.ns.cloudflare.com.
eftydns.com. 5 NS hank.ns.cloudflare.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0