The correct option is 1 and 2 only
Explanation
The Amarkantak plateau serves as a significant watershed in Peninsular India, exhibiting a radial drainage pattern where rivers emerge from a central highland and flow in different directions.
- 1. The Narmada: Correct. The Narmada river originates from the western flank of the Amarkantak plateau in the Anuppur district of Madhya Pradesh. It flows westwards through a rift valley between the Vindhya and Satpura ranges.
- 2. The Son: Correct. The Son river also originates from the Amarkantak plateau. It flows northwards and eventually joins the Ganga river near Patna.
- 3. The Mahanadi: Incorrect. The Mahanadi rises near Sihawa in the Raipur district of Chhattisgarh. While it is part of the peninsular drainage, its source is distinct from the Amarkantak plateau.
- 4. The Tapi: Incorrect. The Tapi originates from Multai in the Betul district of Madhya Pradesh. It flows westwards, parallel to the Narmada but located south of the Satpura range.
Key Takeaway: The Amarkantak plateau is the specific source region for the Narmada and Son rivers. The Mahanadi originates in the highlands of Chhattisgarh (Sihawa), and the Tapi originates in the Betul district (Multai).