37.

Answer and Explanation

Your Answer is

Correct Answer is C

Explanation

Where guides the attributive clause to explain Korea, which is correct.

A item: in which is prone to ambiguity, which can refer to Korea or the tenth and eleventh centuries, so it is wrong.

B item whereas indicates a contrastive relationship, and there is no such logic before and after.

D item past cannot connect the two sentences before and after.