Get sub category

<?php
	$category = get_the_category();
	echo $category[0]->cat_name;
	?>

Does get me a sub category, but the sub category of the wrong parent category..

<?php $cat = get_the_category(); $cat = $cat[0];
	echo(get_category_parents($cat, TRUE, ' &raquo; ')); ?>

Gets me two categories of which one is the wrong parent category and the other a sub category of that same parent..

Well, got a little further:

<?php $cat = get_the_category();
		$parentCatName = get_cat_name($cat[2]->parent);
		echo $parentCatName; ?>

gets me the right parent category, but I need to display $cat[1] when on a sub category of that page. How to do that?

Maybe

<?php echo get_category_parents( get_query_var('cat') , true , '' ); ?>

could work. Just needs a little more work..

<?php
foreach (get_the_category() as $cat) {
 $parent = get_category($cat->category_parent);
 $parent_name = $parent->cat_name;
 $parent_url =  $parent->slug;
}
?>
<?php echo $parent_name; ?>

Shows wrong parent again and does not show the sub category or category child. Maybe I should just get the category..

Got it.

<?php
      foreach((get_the_category( get_the_ID() )) as $category)
        {
           if(cat_is_ancestor_of(get_cat_ID('x') , $category->cat_ID) )
            {
            $category_link = get_category_link( $category->cat_ID );
            $category_name = get_cat_name( $category->cat_ID );
            $Finalcategory = $category;
            break;

           }

       }
       ?>