maximum number of choices in a multiple-choice survey?

[Christian36]

I would like to program a multiple-choice survey - so far no problem. But I can't find a solution to set a minimum number of answers. E.g. maximum choices out of 10 provided options.

The background is to organize a secret online ballot for a board of an association - having more candidates than seats in the board.

any idea?

bests and thanks, Christian