某查询语句运行后返回的结果集为:1班722班75则可能的查询语句是()
A.SELECT class, AVG(score) FROM test WHERE class<3 B.SELECT class, AVG(score) FROM test WHERE class<3 GROUP BY class C.SELECT class, AVG(score) FROM test GROUP BY class HAVING class<3 D.SELECT DISTINCT(class), AVG(score) FROM test WHERE class<3