Select / Dropdown

<form class="custom-drupal-form" accept-charset="UTF-8">
  <div class="form-group js-form-item form-item js-form-type-select form-type-select js-form-item-select form-item-select">
    <label for="edit-select--1" class="js-form-required form-required">Select label</label>
    <select class="form-select form-control" id="edit-select--1" aria-label="Default select example">
      <option selected>Open this select menu</option>
      <option value="1">One</option>
      <option value="2">Two</option>
      <option value="3">Three</option>
    </select>
  </div>
  <div class="form-group js-form-item form-item js-form-type-select form-type-select js-form-item-select form-item-select form-disabled">
    <label for="edit-select--2">Disabled select</label>
    <select class="form-select form-control" id="edit-select--2" aria-label="Default select example" disabled>
      <option selected>Open this select menu</option>
      <option value="1">One</option>
      <option value="2">Two</option>
      <option value="3">Three</option>
    </select>
  </div>
</form>

<form class="themeguide-test-form" data-drupal-selector="themeguide-test-form" action="/themeguide/forms/select?page=3" method="post" id="themeguide-test-form" accept-charset="UTF-8">
  <div class="form-group js-form-item form-item js-form-type-select form-type-select js-form-item-select form-item-select mb-100">
      <label for="edit-select" class="form-label">Select label</label>
        <select data-drupal-selector="edit-select" aria-describedby="edit-select--description" id="edit-select" name="select" class="form-select form-control"><option value="option1">Option 1</option><option value="option2">Option 2</option><option value="option_invalid">Invalid Option</option></select>
                <small id="edit-select--description" class="form-text text-muted description mt-050 d-inline-block">
        This is a description for this field
      </small>
      </div>
<div class="form-group js-form-item form-item js-form-type-select form-type-select js-form-item-select-invalid form-item-select-invalid mb-100">
      <label for="edit-select-invalid" class="form-label">Select Invalid</label>
        <select data-drupal-selector="edit-select-invalid" aria-describedby="edit-select-invalid--description" id="edit-select-invalid" name="select_invalid" class="form-select form-control"><option value="option1">Option 1</option><option value="option2">Option 2</option><option value="option_invalid">Invalid Option</option></select>
                <small id="edit-select-invalid--description" class="form-text text-muted description mt-050 d-inline-block">
        This is a description for this field
      </small>
      </div>
<div class="form-group js-form-item form-item js-form-type-select form-type-select js-form-item-select-required form-item-select-required mb-100">
      <label for="edit-select-required" class="js-form-required form-required form-label">Select Required</label>
        <select data-drupal-selector="edit-select-required" aria-describedby="edit-select-required--description" id="edit-select-required" name="select_required" class="form-select required form-control" required="required" aria-required="true"><option value="" selected="selected">- Select -</option><option value="option1">Option 1</option><option value="option2">Option 2</option><option value="option_invalid">Invalid Option</option></select>
                <small id="edit-select-required--description" class="form-text text-muted description mt-050 d-inline-block">
        This is a description for this field
      </small>
      </div>
<div class="form-group js-form-item form-item js-form-type-select form-type-select js-form-item-select-disabled form-item-select-disabled form-disabled mb-100">
      <label for="edit-select-disabled" class="form-label">Select Disabled</label>
        <select data-drupal-selector="edit-select-disabled" aria-describedby="edit-select-disabled--description" disabled="disabled" id="edit-select-disabled" name="select_disabled" class="form-select form-control"><option value="option1">Option 1</option><option value="option2">Option 2</option><option value="option_invalid">Invalid Option</option></select>
                <small id="edit-select-disabled--description" class="form-text text-muted description mt-050 d-inline-block">
        This is a description for this field
      </small>
      </div>
<input autocomplete="off" data-drupal-selector="form-xphidqd9aznarziuqluliap8zvmawndru0yvwm-8rgu" type="hidden" name="form_build_id" value="form-xpHIdqd9AZnARZiuQlUlIAp8zVmAWnDrU0YvWM-8RgU" />
<input data-drupal-selector="edit-themeguide-test-form" type="hidden" name="form_id" value="themeguide_test_form" />
<div data-drupal-selector="edit-actions" class="form-actions js-form-wrapper form-wrapper" id="edit-actions"><input data-drupal-selector="edit-submit" type="submit" id="edit-submit" name="op" value="Submit" class="button button--primary js-form-submit form-submit btn btn-primary" />
</div>

</form>