Apex domains cannot have CNAME records.
Question and response
Question
dig mc2.run. NS
Answer
mc2.run. 4 NS ns1.zenbox.pl.
mc2.run. 4 NS ns2.zenbox.pl.
Authority
The response has no authority records.
Additional
ns1.zenbox.pl. 4 A 94.152.254.108
ns2.zenbox.pl. 4 A 94.152.255.108
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0