Who is the director of the most popular movie of all time and when was it released? Indicate the average rating score of the users who were on a trialist when they rated the movie.
most popular movie of all time refers to MAX(movie_popularity); a trialist refers to user_trialist = 1; average rating score = AVG(rating_score)
SELECT T1.director_name, T1.movie_release_year , SUM(T2.rating_score) / COUNT(T2.user_id) FROM movies AS T1 INNER JOIN ratings AS T2 ON T1.movie_id = T2.movie_id WHERE T2.user_trialist = 1 ORDER BY T1.movie_popularity DESC LIMIT 1