In which region can you find the top 4 most popular restaurants?
the top 4 most popular restaurant refers to top 4 max(review)
SELECT T2.region FROM generalinfo AS T1 INNER JOIN geographic AS T2 ON T1.city = T2.city ORDER BY T1.review DESC LIMIT 4
database name:db_id restaurant
geographic table geographic Cols: city dtype text, country dtype text, region dtype text, 
generalinfo table generalinfo Cols: id restaurant dtype integer, label dtype text, food type dtype text, city dtype text, review dtype real, 
location table location Cols: id restaurant dtype integer, street number dtype integer, street name dtype text, city dtype text, 
