The ‘Bangar’ of the northern great plain of India is –

The correct answer is (b).

Bangar is a type of soil found in the northern great plain of India. It is composed of old alluvium, which is soil that has been deposited by rivers over a long period of time. Bangar is typically found on the higher terraces of the river valleys, and it is characterized by its dark color, high fertility, and good drainage.

The other options are incorrect. Option (a) is incorrect because bangar is not a wide marshy tract. Option (c) is incorrect because bangar is not a narrow belt along the foot of the Shiwalik. Option (d) is incorrect because bangar is not composed of newer alluvium.