Apex domains cannot have CNAME records.
Question and response
Question
dig 0-24.200.110.124.in-addr.arpa. NS
Answer
0-24.200.110.124.in-addr.arpa. 5 NS ns-205.awsdns-25.com.
0-24.200.110.124.in-addr.arpa. 5 NS ns-1660.awsdns-15.co.uk.
0-24.200.110.124.in-addr.arpa. 5 NS ns-1327.awsdns-37.org.
0-24.200.110.124.in-addr.arpa. 5 NS ns-683.awsdns-21.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0