Apex domains cannot have CNAME records.
Question and response
Question
dig gimenez.ar. NS
Answer
gimenez.ar. 4 NS ns.gimenez.ar.
gimenez.ar. 4 NS ns.moares.ar.
Authority
The response has no authority records.
Additional
ns.gimenez.ar. 4 A 45.177.147.118
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0