Apex domains cannot have CNAME records.
Question and response
Question
dig securednameservers.info. NS
Answer
securednameservers.info. 5 NS ns2.wolverinedns.com.
securednameservers.info. 5 NS ns3.wolverinedns.com.
securednameservers.info. 5 NS ns4.wolverinedns.com.
securednameservers.info. 5 NS ns1.wolverinedns.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0