Apex domains cannot have CNAME records.
Question and response
Question
dig muoso.org. NS
Answer
muoso.org. 5 NS pns72.cloudns.net.
muoso.org. 5 NS pns71.cloudns.net.
muoso.org. 5 NS pns74.cloudns.uk.
muoso.org. 5 NS pns73.cloudns.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0