When a new question appears, how to have all possible answers unchecked?

[nikoagge]

I 've make a simple questionnaire app and I want when I go to a new question, none of the available answers to be selected, obviously I use button.deselectOtherButtons() but I want not to be shown that a button is unchecked when a new question comes out. I even try to use .deselectOtherButtons() on viewDidLoad/viewDidAppear/viewWillAppear but nothing had the result that I 've wanted. Also I tried to find the solution from attributes inspector but with no success. Any suggestions? Thanks in advance.