Among the movies directed by Wolfgang Reitherman, which one of them was the most popular?
directed by Wolfgang Reitherman refers to director = 'Wolfgang Reitherman'; the most popular movie refers to MAX(total_gross);
SELECT T2.movie_title FROM director AS T1 INNER JOIN movies_total_gross AS T2 ON T1.name = T2.movie_title WHERE T1.director = 'Wolfgang Reitherman' ORDER BY T2.total_gross DESC LIMIT 1