You can add some JavaScript to your question text to insert a button that will allow users to reset radio button responses in an array type question.
The link at the bottom of this article will download a text file that contains the script.
To insert the code, edit your question, and click the View Source button in the editor, then insert the JavaScript below your question text:
When you preview your question, you'll see a reset button in at the lower right of your Array type question: