It was raining on the day they arrived.A. in which B. on thatC. on whichD. where

问题补充：

It was raining on the day they arrived.

A. in which

B. on that

C. on which

D. where

答案：

A. in which

B. on that

(答案→)C. on which

D. where

解析：考察定语从句。表示在具体的某一天介词只能用on，当引导词谓语介词后指物时，引导词只能用which，先行词为the day，故选C。