The purpose of the great migration to the west

The ecological environment in the western region is fragile, so it is very important to protect the natural environment and prevent ecological destruction and grassland degradation. At present, it is of great environmental significance to implement "ecological migration" in some parts of western China. It can be seen that the development and construction of the western region must coordinate the relationship between man and land, pay attention to protecting the ecological environment and take the road of sustainable development.

So choose: C.