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. 
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    Susan_Gibson 
Why haven't you made that option choice exclusive.
https://www.qualtrics.com/support/survey-platform/survey-module/editing-questions/formatting-answer-choices/#MakeAnswerExclusiveive
Hope it helps! 
https://community.qualtrics.com/XMcommunity/discussion/comment/52682#Comment_52682I didn't know that was an option thanks Deepak. 
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