Apex domains cannot have CNAME records.
Question and response
Question
dig whoisrockwood.org. NS
Answer
whoisrockwood.org. 5 NS ns-1544.awsdns-01.co.uk.
whoisrockwood.org. 5 NS ns-1922.awsdns-48.co.uk.
whoisrockwood.org. 5 NS ns-484.awsdns-60.com.
whoisrockwood.org. 5 NS ns-1257.awsdns-29.org.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0