Apex domains cannot have CNAME records.
Question and response
Question
dig execulink.net. NS
Answer
execulink.net. 4 NS ns.execulink.com.
execulink.net. 4 NS ns-bmi.execulink.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0