The correct answer is: a) Red soils.
Red soils are the most common type of soil in India. They are well-drained and have a good water retention capacity. They are also rich in nutrients, making them ideal for growing millets, groundnuts, and pulses.
Black soils are also known as regur soils. They are rich in iron and aluminum oxides, which give them their characteristic black color. Black soils are deep and fertile, but they can be difficult to work because they are heavy and sticky. They are best suited for growing crops such as cotton, sugarcane, and sorghum.
Alluvial soils are formed by the deposition of sediments from rivers and streams. They are typically rich in nutrients and have good drainage. Alluvial soils are well-suited for growing a variety of crops, including rice, wheat, and soybeans.
Laterite soils are formed in tropical and subtropical regions with high rainfall. They are rich in iron and aluminum oxides, which give them their characteristic red color. Laterite soils are not very fertile and are prone to erosion. They are best suited for growing crops such as coffee, tea, and rubber.
In conclusion, red soils are the most common type of soil in India and are well-suited for growing millets, groundnuts, and pulses.