Apex domains cannot have CNAME records.
Question and response
Question
dig d279wn0r5doaz5.cloudfront.net. NS
Answer
d279wn0r5doaz5.cloudfront.net. 5 NS ns-1140.awsdns-14.org.
d279wn0r5doaz5.cloudfront.net. 5 NS ns-1696.awsdns-20.co.uk.
d279wn0r5doaz5.cloudfront.net. 5 NS ns-388.awsdns-48.com.
d279wn0r5doaz5.cloudfront.net. 5 NS ns-723.awsdns-26.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0