某查询语句运行后返回的结果集为： 1班 72 2班 75则可能的查询语句是：( )
SELECT class, AVG(score) FROM test WHERE class<3
SELECT class, AVG(score) FROM test WHERE class<3 GROUP BY class
SELECT class, AVG(score) FROM test GROUP BY class HAVING class<3
SELECT DISTINCT(class), AVG(score) FROM test WHERE class<3
