The correct answer is - The region is dominated by desert and high elevations.
Most of the population of China is concentrated in the eastern half of the country, while the western half is very sparsely populated. The main reason for this is the geography and the climate of this part of China.
The western half of the country is dominated by high mountains, the highest in the world actually, the Himalayas, the Tibetan Plateau, deserts and semi arid ares. All of these places are not suitable for living, especially not for larger populations, so there's towns and villages that far away from one another, and they have relatively small populations.
This was the result of the bombings of Hiroshima and Nagasaki
