Apex domains cannot have CNAME records.
Question and response
Question
dig aci.it. NS
Answer
aci.it. 5 NS ns-b.aci.it.
aci.it. 5 NS ns-a.aci.it.
Authority
The response has no authority records.
Additional
ns-a.aci.it. 5 A 77.73.57.14
ns-b.aci.it. 5 A 77.73.57.16
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0