I have a multiple choice question where participants can chose up to 3 answers OR they can chose none of the above. The survey then splits with participants who chose none of the above exiting the survey and people who chose 1-3 of the other answers continuing.
I want to prevent them from using "none of the above" with any of the other options and am trying to show an error message if they do this. I have tried the following and do not get an error message. I can't work out where my logic is wrong.
I'd be grateful if anyone had any idea. Many thanks.