Explanation:

- Option 1: Gandak

- Located in northern India, the Gandak river is a major tributary of the Ganges, not the Yamuna.

- Option 2: Son

- The Son river runs primarily through central India and is also part of the Ganges river system.

- Option 3: Ghaghra

- The Ghaghra is another significant tributary of the Ganges in northern India.

- Option 4: Chambal

- The Chambal river is indeed a major tributary of the Yamuna. It flows through central India before joining the Yamuna river near Etawah in Uttar Pradesh.