Consider the following assertion : In the Pleistocene period either the Yamuna once flowed into the Indus, or the Sutlej flowed into the Yamuna and one major tributary of either had shifted from the Ganga to the Indus or vice versa. Which of the following is/are the basis of the above assertion ? 1. The Nadi-Sukta of the Rigveda 2. The explorations of the Sutlej and the Yamuna by Robert Bruce Foote 3. The presence of the same species of dolphins in both the Indus and the Ganga river systems

Option (D) — 3

• Geologists suggest that a mighty river called Indo-Brahma or Shiwalik traversed the entire longitudinal extent of the Himalayas during the Pleistocene epoch.
• The dismemberment of this river into the Indus, Ganga, and Brahmaputra systems is believed to have been caused by Pleistocene upheavals in the Potwar Plateau.
• The presence of closely related river dolphins, specifically of the Platanista genus, in both the Indus and Ganga river systems serves as strong biological evidence for their historical connection.

• Statement 1. The Nadi-Sukta of the Rigveda: Incorrect. The Nadi-Sukta is a hymn in the Rigveda that praises rivers but provides historical geography, not geological evidence of Pleistocene river shifts.
• Statement 2. The explorations of the Sutlej and the Yamuna by Robert Bruce Foote: Incorrect. Robert Bruce Foote is known as the father of Indian prehistory for discovering Paleolithic tools, not for exploring Pleistocene river shifts of the Sutlej and Yamuna.
• Statement 3. The presence of the same species of dolphins in both the Indus and the Ganga river systems: Correct. The biological distribution of closely related river dolphins in both systems strongly indicates that these rivers were once connected.