Apex domains cannot have CNAME records.
Question and response
Question
dig hit.bme.hu. NS
Answer
hit.bme.hu. 5 NS ara.hit.bme.hu.
hit.bme.hu. 5 NS pavo.hit.bme.hu.
hit.bme.hu. 5 NS nic.bme.hu.
Authority
The response has no authority records.
Additional
nic.bme.hu. 5 A 152.66.115.1
nic.bme.hu. 5 AAAA 2001:738:2001:2001:0:0:0:2
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0