The correct answer is option 4, Tapi. A river delta is a landform that is formed at the mouth of a river where it flows into an ocean, sea, lake, or another river. It is characterized by the deposition of sediment carried by the river, which forms a fan-shaped or triangular landform.
The Ganga (option 1), the Brahmaputra (option 2), and the Godavari (option 3) all form deltas. The Ganga delta is the largest in the world and is situated in Bangladesh. The Brahmaputra forms a delta in Bangladesh as well, and the Godavari delta is located in the Bay of Bengal in India.
However, the Tapi river (option 4) does not form a delta. It flows through the states of Maharashtra and Gujarat in western India and ultimately drains into the Arabian Sea. The Tapi river does not carry enough sediment to form a delta at its mouth.