fieldset optgroup

<form>
  <fieldset>
    <legend>health information</legend>
    height: <input type="text" />
    weight: <input type="text" />
  </fieldset>
</form>

　optgroup   

<select>
      <optgroup label="Swedish Cars">
      <option value ="volvo">Volvo</option>
      <option value ="saab">Saab</option>
      </optgroup>

      <optgroup label="German Cars">
      <option value ="mercedes">Mercedes</option>
      <option value ="audi">Audi</option>
      </optgroup>
</select>