Take the value of a select in a modal and a query

a few days ago a partner helps me to transfer the data from a table to a modal, in them there is a select that receives the status according to the value they have and they are selected. Well but now it is more complicated, I carry the name that the field brings but the select is generated by a while of SQL and I do not know how to make it detect the marked name.

With this we send the content of the span to the modal:

<td class="otrotdfgaz" id="select2-2<?php echo $resta['id']; ?>">
  <?php
    if($resta['idCliente'] == 0) echo "<span>Almacén</span>";
     else{
    ?>
    <span><a href="ver-cliente.php?ID=<?php echo $resta['IdUsuario']; ?>"><?php echo $resta['Nombre']; ?></span></a><span>
  <?php  } ?> 
</td>

With this we pass the value to the id of the select, so that it receives the value:

<script>
   $(document).ready(function(){
    $(document).on('click', '.referencias', function(){
      var id=$(this).val();
      var Stock=$('#select2-2'+id).children('span').first().text();

      $('#referencias').modal('show');
      //alert(Stock);
      if(Stock == 'Almacén')
      $('select#select2-2').val('0').trigger('change');
        else
      $('select#select2-2').val('<?php echo $res['IdUsuario']; ?>').trigger('change');
      });
  });
</script>

With this we receive the value:

 <select id="select2-2" value="" class="form-control" name="select2-2">
     <option value="0">Almacén</option>
   <?php
     //var_dump($_GET);
     $results = $mysqli->query("SELECT * FROM Usuarios");
     mysqli_set_charset("utf8");
      while($res = $results->fetch_array()) {
   ?>
     <option value="<?php echo $res['IdUsuario']; ?>"><?php echo $res['Nombre']; ?></option>
   <?php } ?>                                                        
 </select>