The correct answer is: Alluvial soil.
Alluvial soil is a type of soil that is formed by the deposition of sediments from rivers and streams. It is a rich, fertile soil that is well-drained and easy to work. Alluvial soil is found in many parts of the world, including the Rajmahal region in India.
Laterite soil is a type of soil that is formed in tropical and subtropical regions with high rainfall. It is a reddish-brown soil that is low in nutrients and is not very fertile. Laterite soil is found in many parts of India, including the Deccan Plateau.
Red soil is a type of soil that is formed in tropical and subtropical regions with low rainfall. It is a reddish-brown soil that is rich in iron and aluminum oxides. Red soil is found in many parts of India, including the Deccan Plateau and the Himalayas.
Black soil is a type of soil that is formed in semi-arid regions with a long summer dry season. It is a dark, rich soil that is high in organic matter. Black soil is found in many parts of India, including the Indo-Gangetic Plain.
In conclusion, the correct answer to the question “Which types of soil is found in Rajmahal region?” is Alluvial soil.