Apex domains cannot have CNAME records.
Question and response
Question
dig arrow.com. NS
Answer
arrow.com. 5 NS pdns77.ultradns.biz.
arrow.com. 5 NS dns1.p06.nsone.net.
arrow.com. 5 NS pdns77.ultradns.net.
arrow.com. 5 NS dns4.p06.nsone.net.
arrow.com. 5 NS dns2.p06.nsone.net.
arrow.com. 5 NS dns3.p06.nsone.net.
arrow.com. 5 NS pdns77.ultradns.com.
arrow.com. 5 NS pdns77.ultradns.org.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0