accordion.php

<div class="col-md-9">
        <?php
        $args = array(
            'post_type' => 'acordion',
            'posts_per_page' => '-1',
            'order' => 'ASC'
        );
        $the_query = new WP_Query($args);
        ?>
        <?php $c = 0; ?>

        <div class="panel-group" id="accordion" role="tablist" aria-multiselectable="true">

            <?php
            if ($the_query->have_posts()) : while ($the_query->have_posts()) : $the_query->the_post();
                    $c++;
                    ?>

                    <div class="panel panel-default">
                        <div class="panel-heading" role="tab" id="heading-<?php the_ID(); ?>">
                            <h4 class="panel-title">
                                <a data-toggle="collapse" data-parent="#accordion" href="#collapse-<?php the_ID(); ?>" aria-expanded="true" aria-controls="collapse-<?php the_ID(); ?>">
                                    <?php the_title(); ?>
                                </a>
                            </h4>
                        </div>

                        <div id="collapse-<?php the_ID(); ?>" class="panel-collapse collapse <?php if ($c == 1) echo 'in'; ?>" role="tabpanel" aria-labelledby="heading-<?php the_ID(); ?>">
                            <div class="panel-body">
                                <?php the_excerpt(); ?>
                            </div>
                        </div>
                    </div>


                    <?php
                endwhile;
            else:
                ?>

                <p>Please fill out some questions.</p>

            <?php endif; ?>
            <?php wp_reset_postdata(); ?>
        </div>
    </div>