Apex domains cannot have CNAME records.
Question and response
Question
dig dropmysite.com. NS
Answer
dropmysite.com. 4 NS ns-253.awsdns-31.com.
dropmysite.com. 4 NS ns-1802.awsdns-33.co.uk.
dropmysite.com. 4 NS ns-1092.awsdns-08.org.
dropmysite.com. 4 NS ns-901.awsdns-48.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0