Russia's arable land is mainly distributed in the plains of Eastern Europe. A. Central and East B. Central and South C. East and North D. West and South.

Reason:

1. The western part of Russia is the plain of Eastern Europe, and the plain topography is conducive to the implementation of agricultural mechanization and the improvement of production efficiency;

2. Natural and climatic conditions in western and southern Russia (such as sunshine temperature, irrigation water sources, etc. ) is more suitable for crop growth than other regions, thus increasing grain output;

3. The transportation in western and southern Russia is relatively developed, and these conditions are conducive to the harvesting, transportation and storage of grain.

4. The dense population in western Russia is conducive to reducing the intermediate links of food consumption (transportation, storage, etc.). ).