Apex domains cannot have CNAME records.
Question and response
Question
dig adam.net.au. NS
Answer
adam.net.au. 4 NS seth.adam.com.au.
adam.net.au. 4 NS eden.adam.com.au.
Authority
The response has no authority records.
Additional
eden.adam.com.au. 4 A 203.2.124.2
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0