The following nameservers incorrectly return BADVERS

The following servers for Alexa top 1M names incorrectly return
BADVERS to a DNS query with a EDNS option.

BADVERS is supposed to be used for EDNS version negotiation not
because you see a EDNS option. Please contact your nameserver
vendor for a fix.

This error will result in DNS validation failures if you are
serving signed zones. This error will also result in slower
DNS resolution.