Apex domains cannot have CNAME records.
Question and response
Question
dig ws. NS
Answer
ws. 5 NS ns2.dns.ws.
ws. 5 NS ns5.dns.ws.
ws. 5 NS a.dns.ws.
ws. 5 NS us4.dns.ws.
ws. 5 NS us3.dns.ws.
ws. 5 NS s.dns.ws.
Authority
The response has no authority records.
Additional
a.dns.ws. 171817 A 194.146.106.146
s.dns.ws. 166997 A 77.72.229.248
ns2.dns.ws. 172454 A 64.70.19.80
ns5.dns.ws. 172454 A 64.70.19.70
us3.dns.ws. 172454 A 64.70.78.70
us4.dns.ws. 172454 A 64.70.78.80
a.dns.ws. 171817 AAAA 2001:67c:1010:37:0:0:0:53
s.dns.ws. 166997 AAAA 2a01:3f0:0:311:0:0:0:53
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0