Apex domains cannot have CNAME records.
Question and response
Question
dig alonsa.cl. NS
Answer
alonsa.cl. 5 NS dns.alonsa.cl.
alonsa.cl. 5 NS shelby.cl.
Authority
The response has no authority records.
Additional
dns.alonsa.cl. 5 A 200.54.216.107
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0