Response curation and preference

i'm surprised nobody has suggested this already, i tried searching but couldn't find anything. 

some people who have control of their networks, choose a preference between ipv4 or ipv6 and go as far as to disable one or the other. 

I for example disable ipv6 entirely and only use ipv4. I know some others who do the opposite, and some who use both. users do so for a myriad of reasons, ranging from security, familiarity, performance and the like. 

To that end, my suggestion would be an inclusion of the option to choose what kind of responses you want back. 

First would be an option for a preference toggle.

If the user selects ipv6 then the DNS server will check the request and if the response available has both ipv6 and ipv4 then it will respond with ONLY ipv6. 

If the user selects ipv4 then the DNS server will check the request and if the response available has both ipv6 and ipv4 then it will respond with ONLY ipv4.

in the event of it only having one, it will respond with only that one (or possibly an option for exclusively the user desired response) 

this should also help reduce the amount of query responses. I am exclusive ipv4, so all those AAAA records are useless to me.