Apex domains cannot have CNAME records.
Question and response
Question
dig cat. NS
Answer
cat. 5 NS nsc.nic.de.
cat. 5 NS anyc1.irondns.net.
cat. 5 NS cat.ns.nic.es.
cat. 5 NS cat.pch.net.
cat. 5 NS switch.nic.cat.
Authority
The response has no authority records.
Additional
switch.nic.cat. 55157 A 130.59.31.29
switch.nic.cat. 55157 AAAA 2001:620:0:ff:0:0:0:2f
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0