Why is agricultural production in China distributed in this way?

Much of western China is covered by
A.
dense rain forests.
Much of western China is mountainous
В.
and has a desert climate.
The Huang He frequently floods,
C. destroying farmland in western China.
The Gobi Desert covers western China, making it incapable of supporting farms.

B. and C. The mountainous terrain and desert climate in western China make it difficult to support agricultural production. The frequent flooding of the Huang He river can destroy farmland in the region. The presence of the Gobi Desert also limits the ability to support farms in western China. These geographical factors play a significant role in how agricultural production is distributed in China.