How do I add comment boxes for only some multiple-choice answers? 

Your LimeSurvey version: Cloud Version 6.6
Own server or LimeSurvey hosting: own server
Survey theme/template: fruity
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I am trying to make a multiple choice question where there is more than one comment box but not all the questions have comment boxes (in the example attached I want comment boxes only on the answers that say please specify). How do I do this? I have tried multiple codes that did nothing. Any help would be greatly appreciated, I am a java script novice.