Apex domains cannot have CNAME records.
Question and response
Question
dig medicalxraycenter.com. NS
Answer
medicalxraycenter.com. 4 NS ns-47.awsdns-05.com.
medicalxraycenter.com. 4 NS ns-1079.awsdns-06.org.
medicalxraycenter.com. 4 NS ns-381.awsdns-47.com.
medicalxraycenter.com. 4 NS ns-261.awsdns-32.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0