Apex domains cannot have CNAME records.
Question and response
Question
dig withsecure.com. NS
Answer
withsecure.com. 5 NS usw3.akam.net.
withsecure.com. 5 NS ns1-219.akam.net.
withsecure.com. 5 NS asia2.akam.net.
withsecure.com. 5 NS ns1-221.akam.net.
withsecure.com. 5 NS eur4.akam.net.
withsecure.com. 5 NS usw2.akam.net.
withsecure.com. 5 NS usw6.akam.net.
withsecure.com. 5 NS usc2.akam.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0