Apex domains cannot have CNAME records.
Question and response
Question
dig netsuite.com. NS
Answer
netsuite.com. 3 NS a3-66.akam.net.
netsuite.com. 3 NS a1-124.akam.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0