Apex domains cannot have CNAME records.
Question and response
Question
dig yewpingchin.com. NS
Answer
yewpingchin.com. 4 NS ns2.yewpingchin.com.
yewpingchin.com. 4 NS ns1.yewpingchin.com.
Authority
The response has no authority records.
Additional
ns1.yewpingchin.com. 4 A 91.246.221.166
ns2.yewpingchin.com. 4 A 67.215.247.195
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0