Which company published the game with the most sales in North America?
company refers to publisher_name; the most sales refers to max(num_sales); in North America refers to region_name = 'North America'
SELECT T.publisher_name FROM ( SELECT T5.publisher_name, SUM(T2.num_sales) * 100000 FROM region AS T1 INNER JOIN region_sales AS T2 ON T1.id = T2.region_id INNER JOIN game_platform AS T3 ON T2.game_platform_id = T3.id INNER JOIN game_publisher AS T4 ON T3.game_publisher_id = T4.id INNER JOIN publisher AS T5 ON T4.publisher_id = T5.id WHERE T1.region_name = 'North America' GROUP BY T5.publisher_name ORDER BY SUM(T2.num_sales) * 100000 DESC LIMIT 1 ) t