<div class="container mt-5 pt-5">

  <select class="select">

    <option value="" hidden >placeholder</option>

    <option value="1">One</option>

    <option value="2">Two</option>

    <option value="3">Three</option>

    <option value="4">Four</option>

    <option value="5">Five</option>

  </select>

</div>