Apex domains cannot have CNAME records.
Question and response
Question
dig org.tw. NS
Answer
org.tw. 2 NS h.twnic.net.tw.
org.tw. 2 NS c.twnic.net.tw.
org.tw. 2 NS b.twnic.net.tw.
org.tw. 2 NS h.dns.tw.
org.tw. 2 NS a.twnic.net.tw.
org.tw. 2 NS e.twnic.net.tw.
org.tw. 2 NS g.twnic.net.tw.
org.tw. 2 NS f.twnic.net.tw.
org.tw. 2 NS d.twnic.net.tw.
org.tw. 2 NS anytld.apnic.net.
Authority
The response has no authority records.
Additional
h.dns.tw. 172713 A 204.61.216.119
h.dns.tw. 172713 AAAA 2001:500:14:6119:ad:0:0:1
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0