Apex domains cannot have CNAME records.
Question and response
Question
dig telrad.biz. NS
Answer
telrad.biz. 4 NS ns1.telrad.net.
telrad.biz. 4 NS ns2.telrad.net.
telrad.biz. 4 NS ns3.telrad.net.
Authority
The response has no authority records.
Additional
ns1.telrad.net. 4 A 77.239.64.19
ns2.telrad.net. 4 A 77.239.64.20
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0