code: protected function addContentTagToOpenTags(&$tag)
      {
          if ($tag->getTagName() != 'option') {
              return;
          }
          foreach (array_keys($this->tags) as $name) {
              for ($i = 0, $count = count($this->tags[$name]); $i < $count; $i++) {
                  $this->tags[$name][$i]->addTag($tag);
              }
          }
      }
docs: Parsed data in tag form.
  The parsed tag is added to every open tag.
  Used for adding options to select fields only.
  
  @param SimpleTag $tag        Option tags only.