Apex domains cannot have CNAME records.
Question and response
Question
dig nifty.com. NS
Answer
nifty.com. 4 NS odns0.nifty.ad.jp.
nifty.com. 4 NS odns2.nifty.ad.jp.
nifty.com. 4 NS odns1.nifty.ad.jp.
Authority
The response has no authority records.
Additional
odns0.nifty.ad.jp. 4 A 210.225.239.167
odns1.nifty.ad.jp. 4 A 52.195.123.149
odns2.nifty.ad.jp. 4 A 15.168.78.62
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0