某钢构件厂家根据供货合同先后生产了4批钢构件,各批次的质量统计直方图如下所示。其中已经出现不合格构件,必须采取措施纠偏的是( )。
A <img src="https://www.beizhujiaoyu.com/uploads/202208/20170901174632_0157.png" alt="" title="" width="180" height="182" align="" /> B <img src="https://www.beizhujiaoyu.com/uploads/202208/20170901174641_9963.png" alt="" title="" width="180" height="172" align="" /> C <img src="https://www.beizhujiaoyu.com/uploads/202208/20170901174718_4503.png" alt="" title="" width="180" height="175" align="" /> D <img src="https://www.beizhujiaoyu.com/uploads/202208/20170901174731_0784.png" alt="" title="" width="180" height="165" align="" />