Apex domains cannot have CNAME records.
Question and response
Question
dig us-east-1.elasticbeanstalk.com. NS
Answer
us-east-1.elasticbeanstalk.com. 5 NS ns-1011.awsdns-62.net.
us-east-1.elasticbeanstalk.com. 5 NS ns-59.awsdns-07.com.
us-east-1.elasticbeanstalk.com. 5 NS ns-1846.awsdns-38.co.uk.
us-east-1.elasticbeanstalk.com. 5 NS ns-1219.awsdns-24.org.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0