Apex domains cannot have CNAME records.
Question and response
Question
dig ya.com. NS
Answer
ya.com. 4 NS dns4.wanadoo.es.
ya.com. 4 NS dns1.wanadoo.es.
Authority
The response has no authority records.
Additional
dns1.wanadoo.es. 4 A 62.37.237.140
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0