Apex domains cannot have CNAME records.
Question and response
Question
dig a1hosting.bg. NS
Answer
a1hosting.bg. 5 NS ns1.a1hosting.bg.
a1hosting.bg. 5 NS ns2.a1hosting.bg.
Authority
The response has no authority records.
Additional
ns1.a1hosting.bg. 5 A 212.50.0.10
ns2.a1hosting.bg. 5 A 212.50.0.15
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0