        <option value="11">November</option>
        <option value="12">December</option>
      </select>
    </div>
  </div>

  <hr>

  <div class="mb-3 row">
    <label class="col-sm-2">
      Group Select
    </label>

    <div class="col-sm-10">
      <select multiple="multiple">
        <optgroup label="Group 1">
          <option value="1">Option 1</option>
          <option value="2">Option 2</option>
          <option value="3">Option 3</option>
        </optgroup>
        <optgroup label="Group 2">