Apex domains cannot have CNAME records.
Question and response
Question
dig pacific.net.sg. NS
Answer
pacific.net.sg. 5 NS dns1.pacific.net.sg.
pacific.net.sg. 5 NS dns2.pacific.net.sg.
pacific.net.sg. 5 NS dns3.pacificinternet.com.
Authority
The response has no authority records.
Additional
dns1.pacific.net.sg. 5 A 203.120.90.91
dns2.pacific.net.sg. 5 A 203.81.36.92
dns3.pacificinternet.com. 5 A 210.24.236.53
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0