Apex domains cannot have CNAME records.
Question and response
Question
dig wip4.adobe.com. NS
Answer
wip4.adobe.com. 5 NS sj1gtm003.adobe.com.
wip4.adobe.com. 5 NS sj1gtm004.adobe.com.
wip4.adobe.com. 5 NS or1gtm004.adobe.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0