populating dropdown based in first selection - ajax

Question

My COntroller
public function gettestRecieve() {
$test = array('recieve' => $this->input->post('recieve'));
$data = $this->test->getrecieve($test);
echo json_encode($data);
}
My Model
function getAcademic($test) {
$this->db->select('a_y');
$this->db->where($test);
$this->db->distinct();
$result = $this->db->get('table');
$return = array();
if($result->num_rows() > 0){
$return[''] = 'select';
foreach($result->result_array() as $row){
$return[$row['a_y']] = $row['a_y'];
}
}
return $return;
}
My view
$(document).ready(function () {
$('#test').change(function () {
var add = $(this).val();
//console.log(add);
$.ajax({
url: "<?php echo base_url();?>getAcademic",
method: "POST",
data: {testing: add},
success: function(add) {
var data = JSON.parse(add);//parse response to convert into onject
console.log(data);//see your result in console
//alert(data[0].Ayear);
$('#good').html('<option value="'+ Ayear +'" >'+ Ayear +'</option>');
}
})
});
});
this gives me an error object HTMLSelectElement what does it mean, when i tried to look at my console it gives me a right value {"": "A & Y", 2014-2015: "2014-2015"} but in frontend gives an error, how could i fix this! can someone know this error, thanks and advanced