4.2

<select name="id_kelas">
    <option value="">[ Pilih Option ]</option>
    <?php while ($siswa = mysqli_fetch_object($dataKelas)) { ?>
    <option value="<?php echo $siswa->id_kelas?>"
     <?php echo @$action->id_kelas == $siswa->id_kelas ? 'selected' : '' ?> >
     <?php echo $siswa->nama_kelas?>
    </option>
    <?php } ?>
    </select>