Apex domains cannot have CNAME records.
Question and response
Question
dig saipan.com. NS
Answer
saipan.com. 4 NS ns.guam.net.
saipan.com. 4 NS ns.saipan.com.
Authority
The response has no authority records.
Additional
ns.guam.net. 4 A 202.128.7.1
ns.saipan.com. 4 A 202.128.27.2
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0