In what part of china did the population decrease the most? in the northeast in the northwest in the southeast in the southwest

In the northwest of China the population decreases the most. Option B is correct.

The northwestern part of China is one of the most inhospitable places for living in the country since it is characterized by extreme temperatures, presence of desert as well as dry steppes.

Northwestern China includes the autonomous regions of Xinjiang and Ningxia and the provinces of Shaanxi, Gansu, and Qinghai.

the two major parties acting together and cooperating when making decisions is bipartisan