Apex domains cannot have CNAME records.
Question and response
Question
dig c72017.sgvps.net. NS
Answer
c72017.sgvps.net. 1 NS ns1.c72017.sgvps.net.
c72017.sgvps.net. 1 NS ns2.c72017.sgvps.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0