The rise of Qidan refers to the Song Dynasty.

Peace and war in Liao, Song and Xia were in Liao, Song and Xia.

Therefore, the reunification of country A is wrong and irrelevant.

C China's family unity is wrong, it is not mentioned, and it is not obvious from the material.

The prosperity that country D strives for is far-fetched.

Only the coexistence of regime in country B can be optimized.

It is my question that I will give this option: ethnic exchange or integration, which I think is better.