Source

File: wp-includes/category-template.php

function get_category_parents( $category_id, $link = false, $separator = '/', $nicename = false, $deprecated = array() ) {

	if ( ! empty( $deprecated ) ) {
		_deprecated_argument( __FUNCTION__, '4.8.0' );
	}

	$format = $nicename ? 'slug' : 'name';

	$args = array(
		'separator' => $separator,
		'link'      => $link,
		'format'    => $format,
	);

	return get_term_parents_list( $category_id, 'category', $args );
}