Apex domains cannot have CNAME records.
Question and response
Question
dig careerade.com. NS
Answer
careerade.com. 5 NS ns-1500.awsdns-59.org.
careerade.com. 5 NS ns-1566.awsdns-03.co.uk.
careerade.com. 5 NS ns-276.awsdns-34.com.
careerade.com. 5 NS ns-1015.awsdns-62.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0