nested forloop error in php codeigniter

<?php foreach ($faq as $faq): ?>
    <div class="form-group firstedit">
        <label class="col-sm-2 control-label">Question : </label>
        <div class="col-sm-8">
            <input type="text" id="question" class="form-control remove_att" value="<?php echo $faq['faq_question'] ?>" placeholder="Enter the question" readonly="readonly" required="">
        </div>
        <div class="col-sm-8">
            <select data-plugin-selectTwo class="form-control populate" id="category" required="required">
                <?php foreach ($category as $category){ ?>
                    <option value="<?php echo $category['faq_category_id'] ?>"><?php echo $category['faq_category_name'] ?></option>
                <?php } ?>
            </select>
        </div>
        <div class="col-sm-2" class="edit_all">
            <button type="button" class="btn btn-warning btn-sm show_edit" data-toggle="tooltip" data-placement="bottom" title="Edit"><i class="fa fa-edit"></i></button>
            <button type="button" id="<?php echo $faq['faq_id'] ?>" class="btn btn-success btn-sm save_faq" data-toggle="tooltip" data-placement="bottom" title="Save" style="display: none"><i class="fa fa-floppy-o" ></i></button>
            <button  type="button"  class="btn btn-danger btn-sm delete_faq"  id="<?php echo $faq['faq_id'] ?>" data-toggle="tooltip" data-placement="bottom" title="Delete"><i class="fa fa-trash"></i>&nbsp;Delete</button>
        </div>
    </div>
    <div class="form-group answer">
        <label class="col-sm-2 control-label">Answer : </label>
        <div class="col-sm-8 edit_answer" >
            <textarea class="form-control remove_text" id="answer11" rows="5" placeholder="Type your answer..." required="required" readonly ><?php echo $faq['faq_answer'] ?></textarea>
        </div>
        <div class="col-sm-2">
            <?php if ($faq['faq_status'] == "pending") : ?>
                <button  type="button"  class="btn btn-danger btn-sm approve_faq"  id="<?php echo $faq['faq_id'] ?>" data-toggle="tooltip" data-placement="bottom" title="Approve FAQ's"><i class="fa fa-trash"></i>&nbsp;approve</button>
            <?php endif; ?>
        </div>
    </div>
<?php endforeach; ?>

my controller

public function not_approved() {
        $category_id = $this->input->post('category_id');
        $data['faq'] = $this->faq_model->not_approved($category_id);
         // get the faq category
        $data['category'] = $this->faq_model->get_category();
       // echo "<script>alert('adadsdsa')</script>";
        $this->load->view('faq/display_faq_not_approved', $data);
    }

I have for-loop for FAQ where display all the FAQ values and I have FAQ category, but in separate table.

I want to display the FAQ category. above I use the nested for-loop but end with an error.

I want to display the nested for loop with in the for-loop for displaying all the category. how to achieve this