Listing categories for recent posts, need help…

I’m struggling to know the correct function to list categories in this loop:

<div class="row-3-row-3-col-1">

	<?php
	$args = array( 'numberposts' => 1 );
	$lastposts = get_posts( $args );
	foreach($lastposts as $post) : setup_postdata($post); ?>

		<h2><a href="<?php the_permalink(); ?>"><?php the_title(); ?></a></h2>
		<p class="post-meta"><i>By</i> <?php the_author(); ?> <i>in</i> </p>
		<p><?php the_excerpt(); ?></p>

	<?php endforeach; ?>

</div>

<!-- BEGINNING OF ROW-3-ROW-3-COL-2 -->
<div class="row-3-row-3-col-2">

	<?php
	$args = array( 'numberposts' => 1, 'offset' => 1 );
	$lastposts = get_posts( $args );
	foreach($lastposts as $post) : setup_postdata($post); ?>

		<h2><a href="<?php the_permalink(); ?>"><?php the_title(); ?></a></h2>
		<p class="post-meta"><i>By</i> <?php the_author(); ?> <i>in</i> <?php the_category(); ?></p>
		<p><?php the_excerpt(); ?></p>

	<?php endforeach; ?>

</div>

Specifically, I want to remove the ul/li and have them just be links separated by a comma. Can anyone help? Thank you!