Apex domains cannot have CNAME records.
Question and response
Question
dig drmarsha.com. NS
Answer
drmarsha.com. 5 NS ns-556.awsdns-05.net.
drmarsha.com. 5 NS ns-132.awsdns-16.com.
drmarsha.com. 5 NS ns-170.awsdns-21.com.
drmarsha.com. 5 NS ns-2028.awsdns-61.co.uk.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0