Apex domains cannot have CNAME records.
Question and response
Question
dig state.ar.us. NS
Answer
state.ar.us. 5 NS dns4.state.ar.us.
state.ar.us. 5 NS dns5.state.ar.us.
state.ar.us. 5 NS dns1.state.ar.us.
state.ar.us. 5 NS dns2.state.ar.us.
state.ar.us. 5 NS dns3.state.ar.us.
Authority
The response has no authority records.
Additional
dns1.state.ar.us. 5 A 170.94.1.1
dns2.state.ar.us. 5 A 150.208.10.26
dns3.state.ar.us. 5 A 165.29.1.1
dns4.state.ar.us. 5 A 66.204.1.66
dns5.state.ar.us. 5 A 66.204.193.26
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0