Apex domains cannot have CNAME records.
Question and response
Question
dig nac.net. NS
Answer
nac.net. 5 NS ns2.nac.net.
nac.net. 5 NS ns1.nac.net.
Authority
The response has no authority records.
Additional
ns1.nac.net. 5 A 207.99.0.1
ns2.nac.net. 5 A 207.99.0.2
ns1.nac.net. 5 AAAA 2001:518:0:0:0:0:0:1
ns2.nac.net. 5 AAAA 2001:518:0:0:0:0:0:2
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0