<script type="text/javascript" charset="utf-8">
  $(document).ready(function(){  
 
    // Add a class to the question
    $('#question{QID}').addClass('with-separator-options');
 
    // Loop through all dropdowns in this question
    $('#question{QID} .answer-item select').each(function(i) {
      // Insert a separator before the option with value 1
      $('option[value="1"]', this).before('<option value="" disabled>Separator 1</option>');
 
      // Insert a separator before the option with value 5
      $('option[value="5"]', this).before('<option value="" disabled>Separator 2</option>');
    });
  });
</script>

.with-separator-options .answer-item option {
  padding: 0 15px;
}
 
.with-separator-options .answer-item option:disabled {
  padding: 0;
  font-weight: bold;
  opacity: 1;
  color: #000000;
}