Which one of the following east flowing rivers of India has rift valley due to down warping?

1. The question asks to identify an east flowing river of India that flows through a rift valley formed due to down warping. 2. Rift valleys in India are typically associated with the Narmada and Tapti rivers, which flow westward. 3. However, the Damodar river, an east flowing river (tributary of Hooghly), flows through the Chotanagpur Plateau region. 4. The Damodar valley is considered a rift valley or a structural trough formed due to faulting and down warping during the Gondwana period. It is rich in coal deposits, typical of such formations. 5. Mahanadi, Sone (flows north then joins Ganga), and Yamuna do not flow through prominent rift valleys.