Apex domains cannot have CNAME records.
Question and response
Question
dig ucla.edu. NS
Answer
ucla.edu. 5 NS ns1.dns.ucla.edu.
ucla.edu. 5 NS ns4.dns.ucla.edu.
ucla.edu. 5 NS ns3.dns.ucla.edu.
ucla.edu. 5 NS ns2.dns.ucla.edu.
Authority
The response has no authority records.
Additional
ns1.dns.ucla.edu. 5 A 192.35.225.7
ns2.dns.ucla.edu. 5 A 54.201.38.106
ns3.dns.ucla.edu. 5 A 54.236.209.157
ns4.dns.ucla.edu. 5 A 3.104.50.254
ns1.dns.ucla.edu. 5 AAAA 2607:f010:3fe:12:0:ff:fe01:35
ns2.dns.ucla.edu. 5 AAAA 2600:1f14:793:a600:0:0:0:53
ns3.dns.ucla.edu. 5 AAAA 2600:1f18:21d4:e000:0:0:0:53
ns4.dns.ucla.edu. 5 AAAA 2406:da1c:e21:8600:0:0:0:53
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0