To allow DNS to resolve, you only need one DNS listener IP: TCP and UDP
-How to setup a DNS Zone
You are wanting to load balance multiple internal DNS servers and have one external IP to "listen" for DNS requests.
VIP(Public IP) -> Pool(multiple Private IP DNS servers)
Nslookup will show the DNS server's IP that is configured on your box (ipconfig /all DNS IP) and it will show the Non-Authoritive resolution for the FQDN you are looking up.
PS F:> nslookup foobar.com
Server: lala.meow.blahblah.com
Address: 10.1.1.11 <---My local Private IP DNS server seen via "ipconfig"
Non-authoritative answer:
Name: foobar.com
Address: 162.241.216.134
Google search to help understand "Recursive DNS"