Apex domains cannot have CNAME records.
Question and response
Question
dig interbusiness.it. NS
Answer
interbusiness.it. 1 NS dns9.interbusiness.it.
interbusiness.it. 1 NS dns10.interbusiness.it.
Authority
The response has no authority records.
Additional
dns9.interbusiness.it. 1 A 80.22.52.133
dns10.interbusiness.it. 1 A 217.169.119.68
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0