Apex domains cannot have CNAME records.
Question and response
Question
dig stablehost.com. NS
Answer
stablehost.com. 2 NS aron.ns.cloudflare.com.
stablehost.com. 2 NS carl.ns.cloudflare.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0