How to show cutom post labels in options?

Question

I have this code:

      $args=array(
        'public'   => true,
        '_builtin' => false
      );
      ?>
      <select id="<?php echo $this->get_field_id('posttype'); ?>" name="<?php echo $this->get_field_name('posttype'); ?>">
          <?php foreach(get_post_types($args,'names') as $post_type) { ?>
              <option <?php selected( $instance['posttype'], $post_type ); ?> value="<?php echo $post_type; ?>"><?php echo $post_type; ?></option>
          <?php } ?>      
      </select>

I make custom posts

function my_post_type_interior_articles() {
        register_post_type( 'interior_articles',
                    array( 
                    'label' => __('Interior Design Articles'), 
                    'public' => true, 
                    'show_ui' => true,
                    'show_in_nav_menus' => false,
                    'menu_position' => 5,
                    'supports' => array(
                            'title',
                            'custom-fields',
                            'editor',
                            'excerpt',
                            'thumbnail')
                        ) 
                    );
    }

    add_action('init', 'my_post_type_interior_articles');

in dropdown shows "interior_articles", but i need to show "Interior Design Articles"

How to show cutom post labels in options?