He didn't put the things where they belonged,in ________ case everything was out of order.A that B what C whose D which为什么选D

He didn't put the things where they belonged,in ________ case everything was out of order.A that B what C whose D which为什么选D
He didn't put the things where they belonged,
in ________ case everything was out of order.
A that B what C whose D which
为什么选D

He didn't put the things where they belonged,in ________ case everything was out of order.A that B what C whose D which为什么选D
in which case,是固定短语,意思是在这种情况下
in that case,也是固定短语,意思是如果是那样的话,表假设
你结合语意就可以理解了：他没有把东西放回原处,在这种情况下,东西都乱了.

说的是在哪种情况下呗，what case是中国式英语