Apex domains cannot have CNAME records.
Question and response
Question
dig selcomm.com. NS
Answer
selcomm.com. 4 NS name3.selcomm.com.
selcomm.com. 4 NS name1.selcomm.com.
selcomm.com. 4 NS name2.selcomm.com.
Authority
The response has no authority records.
Additional
name1.selcomm.com. 4 A 220.233.156.30
name2.selcomm.com. 4 A 203.202.109.94
name3.selcomm.com. 4 A 203.111.104.222
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0