वाणिज्यिक अनाज कृषि प्रमुख रूप से किन क्षेत्रों में की जाती है?

Match the types of farming with their corresponding regions: List I (Types of Farming): A. Shifting cultivation B. Commercial grain farming C. Intensive subsistence agriculture D. Nomadic herding List II (Areas/Regions): I. Semi-arid and arid regions II. Thickly populated areas III. Thickly forested areas IV. Temperate Grasslands

Which country is the largest producer of barley in the world?