By this code ,it shows all the category.but i want to show specific some category(like-Officer,Training) Thanks in Advance

    <?php 
        // change category to your custom page slug
        $categories = get_categories(); 
        foreach ($categories as $category) {
            $option .= '<option value="'.get_option('home').'/category/'.$category->slug.'">';
            $option .= $category->cat_name;
            $option .= ' ('.$category->category_count.')';
            $option .= '</option>';
        }
        echo $option;
    ?>
</select>