Bootstrap手风琴最后一项始终打开：怎么样？

I have a Bootstrap accordion on my site in an ACF repeater. The first entry is always open. Instead of the first entry, I would like to have the last entry to be always open.

Because the last entry isn't always a fixed number The last entry can be the 5th entry of the second entry. How to fix this?

Please see the code below:

<?php if( have_rows('faq') ): ?>
<div id="accordion" role="tablist">
  <?php $i=1; while ( have_rows('faq') ) : the_row(); ?>
    <div class="card">
        <div class="card-header" role="tab" id="heading-<?php echo $i; ?>">
          <h5 class="mb-0">
            <a data-toggle="collapse" href="#collapse-<?php echo $i; ?>" aria-expanded="true" aria-controls="collapseOne">
             <?php the_sub_field('vraag'); ?>
            </a>
          </h5>
        </div>
        <div id="collapse-<?php echo $i; ?>" class="collapse <?php if ($i==1) { echo 'show'; } ?>" role="tabpanel" data-parent="#accordion" aria-labelledby="heading-<?php echo $i; ?>">
          <div class="card-body">
            <?php the_sub_field('antwoord'); ?>
          </div>
        </div>
    </div>
  <?php $i++; endwhile; ?>
</div>