Apex domains cannot have CNAME records.
Question and response
Question
dig dz. NS
Answer
dz. 5 NS ns-dz.afrinic.net.
dz. 5 NS ns4.nic.dz.
dz. 5 NS ns1.nic.dz.
dz. 5 NS ns3.nic.fr.
dz. 5 NS ns2.nic.dz.
dz. 5 NS ns5.nic.dz.
Authority
The response has no authority records.
Additional
ns4.nic.dz. 51674 A 204.61.216.103
ns5.nic.dz. 81198 A 193.0.9.71
ns4.nic.dz. 51674 AAAA 2001:500:14:6103:ad:0:0:1
ns5.nic.dz. 81198 AAAA 2a13:27c0:30:0:0:0:0:71
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0