Apex domains cannot have CNAME records.
Question and response
Question
dig r4ns.com. NS
Answer
r4ns.com. 5 NS ns2.r4ns.net.
r4ns.com. 5 NS ns1.r4ns.com.
Authority
The response has no authority records.
Additional
ns1.r4ns.com. 5 A 176.124.112.100
ns2.r4ns.net. 5 A 176.124.113.200
ns1.r4ns.com. 5 AAAA 2a05:b0c0:0:0:0:0:0:100
ns2.r4ns.net. 5 AAAA 2a05:b0c1:0:0:0:0:0:200
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0