Apex domains cannot have CNAME records.
Question and response
Question
dig dot.ph. NS
Answer
dot.ph. 5 NS serena.ns.cloudflare.com.
dot.ph. 5 NS chris.ns.cloudflare.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0