Apex domains cannot have CNAME records.
Question and response
Question
dig cream.sk. NS
Answer
cream.sk. 5 NS ns.cream.sk.
cream.sk. 5 NS ns3.cream.sk.
cream.sk. 5 NS ns2.cream.sk.
Authority
The response has no authority records.
Additional
ns.cream.sk. 5 A 217.73.26.189
ns2.cream.sk. 5 A 46.229.239.226
ns3.cream.sk. 5 A 35.157.167.53
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0