Apex domains cannot have CNAME records.
Question and response
Question
dig solver.net. NS
Answer
solver.net. 5 NS chichi.ns.giantpanda.com.
solver.net. 5 NS panpan.ns.giantpanda.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0