Apex domains cannot have CNAME records.
Question and response
Question
dig powerhost.bg. NS
Answer
powerhost.bg. 5 NS ns2.powerhostbg.com.
powerhost.bg. 5 NS ns1.powerhostbg.com.
Authority
The response has no authority records.
Additional
ns1.powerhostbg.com. 5 A 78.128.60.97
ns2.powerhostbg.com. 5 A 78.128.60.97
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0