Explanation:

- The Paithan Hydro-Electric Project is located on a specific river that supports its operations.

- Option 1: Brahmaputra

- The Brahmaputra is a major river flowing in northeast India.

- It's not associated with the Paithan project.

- Option 2: Yamuna

- The Yamuna is a significant river in northern India, but not related to this project.

- Option 3: Narmada

- The Narmada flows through central India and hosts other hydro projects.

- Option 4: Godavari

- The Godavari is one of the longest rivers in India, running through Maharashtra where Paithan is located.

- The Paithan Hydro-Electric Project is indeed on the Godavari River.