<script type="text/javascript" charset="utf-8">
 
  $(document).on('ready pjax:scriptcomplete',function(){
    // Identify this question
    var thisQuestion = $('#question{QID}');
 
    var defaultCode = 0;
 
    // Loop through the rows
    $('tr.answers-list', thisQuestion).each(function(i) {
      var thisRow = $(this);
 
      // Set default answer
      if($('input:radio:checked', thisRow).length == 0) {
        $('input:radio[value="'+defaultCode+'"]', thisRow).trigger('click');
      }
    });
  });
</script>