Apex domains cannot have CNAME records.
Question and response
Question
dig pingability.com. NS
Answer
pingability.com. 3 NS ns1.rimuhosting.com.
pingability.com. 3 NS ns2.rimuhosting.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0