Apex domains cannot have CNAME records.
Question and response
Question
dig manalink.com.br. NS
Answer
manalink.com.br. 5 NS ns616.hostgator.com.br.
manalink.com.br. 5 NS ns617.hostgator.com.br.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0