The correct answer is D. Terai Soil.
Terai soil is a type of alluvial soil found in the Terai region of Nepal and India. It is a fertile soil that is well-drained and has a high organic content. The soil is ideal for growing rice, sugarcane, and other crops.
Mountain soil is a type of soil found in mountainous regions. It is a thin soil that is poor in nutrients and organic matter. The soil is often rocky and difficult to cultivate.
Kachari soil is a type of soil found in the Kachari Hills of Assam, India. It is a red soil that is rich in iron and aluminum. The soil is not very fertile and is often used for grazing.
Regur soil is a type of soil found in the Deccan Plateau of India. It is a black soil that is rich in calcium carbonate. The soil is very fertile and is used for growing cotton, sugarcane, and other crops.