Apex domains cannot have CNAME records.
Question and response
Question
dig rank.com.co. NS
Answer
rank.com.co. 5 NS ns8.wixdns.net.
rank.com.co. 5 NS ns9.wixdns.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0