单选题 用某种排序方法对数据序列(24, 88, 21, 48, 15, 27, 69, 35, 20)进行递增排序,元素序列的变化情况如下: ① (24, 88, 21, 48, 15, 27, 69, 35, 20) ② (20, 15, 21, 24, 48, 27, 69, 35, 88) ③ (15, 20, 21, 24, 35, 27, 48, 69, 88) ④ (15, 20, 21, 24, 27, 35, 48, 69, 88) 则所采用的排序方法是( )