The correct option is (b).
Explanation
Commercial Grain Farming is a form of extensive agriculture practiced in the mid-latitudes. It is characterized by high mechanization, large farm sizes, and a focus on market-oriented production rather than subsistence.
Statement 1 is Incorrect:
Commercial grain farming is practiced in sparsely populated regions of the world, such as the North American Prairies, the Argentinian Pampas, and the Eurasian Steppes. The large landholdings required for this mechanized farming are not feasible in thickly populated areas, where intensive subsistence agriculture is more common.
Statement 2 is Correct:
Wheat is the principal crop grown in this system. However, other grains such as maize, barley, oats, and rye are also commonly cultivated for commercial purposes depending on the specific region.
Statement 3 is Incorrect:
This type of farming is typically found in temperate grasslands with semi-arid conditions. The winters are often severe, which restricts the growing season. Consequently, only a single crop can be grown annually. The climate does not support multiple cropping throughout the year.
Key Takeaway:
Commercial Grain Farming is distinct for its extensive land use in sparsely populated temperate grasslands, high degree of mechanization, and monoculture (single crop per year), primarily wheat.