Apex domains cannot have CNAME records.
Question and response
Question
dig chip4.greengeeks.net. NS
Answer
chip4.greengeeks.net. 5 NS chi-ns2.websitehostserver.net.
chip4.greengeeks.net. 5 NS chi-ns1.websitehostserver.net.
chip4.greengeeks.net. 5 NS ams-ns1.websitehostserver.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0