Hope you need something like this.
<?php
$row->is_sponsored_by = 'y';//already stored value
$dropDnArr = array('y' => 'Yes', 'n' => 'No');//Say y & n storing DB And Yes & No is to display
echo "selected value ={$row->is_sponsored_by}<br/>"; ?>
<label>Get Sponsored <span style="color:red">*</span></label>
<select style="width:100px;" class="form-control" name="sponsor"> <?php
foreach ($dropDnArr AS $key => $value) {?>
<option value="<?php echo $key;?>"
<?php echo (isset($row)) ? (($row->is_sponsored_by == $key) ? "selected" : "") : "";?> >
<?php echo $value;?>
</option> <?php
} ?>
</select>