如何在html和css中的下拉菜单之间放置空格？

<select>
  <option>Option 1</option>
  <option>Option 2</option>
  <option>&nbsp;&nbsp;&nbsp;Option 3</option>
  <option>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Option 4</option>
</select>

<style>
  select option {
    padding-left: 20px;
  }
</style>

<select>
  <option>Option 1</option>
  <option>Option 2</option>
  <option>Option 3</option>
  <option>Option 4</option>
</select>