The Deccan Plateau rises to 100 metres in the North, and to more than 1,000 metres in the South, forming a raised triangle. The Malwa plateau dominates the Vindhya scraps, forming the northern (not the eastern) flank of the plateau. So, statement (2) is incorrect. The Chota Nagpur Plateau (22°-25° 30'N and 83°47'-87° 50'E) includes Ranchi, Hazaribagh, Singhbhum, Dhanbad, Palamu, Santhal Parganas and Purulia districts (West Bengal). It is composed of Archaean granite and gneiss rocks with patches of Dharwar rocks (phyllite, micaschists). So, statement (4) is correct. This automatically makes option (b) the correct answer.