Add exclusive option for choosing more than one

I have a usecase where there are several options to be voted on, User can choose up to a set number. However among the options is "none of the above". When we use paper ballots if you choose none of the above AND chose other options the ballot is considered spoiled. I can't see a way to do this with the polling feature. (I plan on going into the mysql database to see if any votes are invalid after the fact)

So it would be nice to have an "exclusive" option for the choices where if the userr chooses this the others are all deselected and disabled.

Another way to skin this cat would be to publish (or allow poll creators to assign) the component id for each checkbox and then allow for poll creators to insert their own custom javascript in some way. (another joomla form creator I use has this feature)