Which one of the following is not a tidal river of West Bengal?

Correct answer: Ajay

Explanation: The correct answer is C. Ajay. The Ajay River is a non-tidal, rain-fed river that originates from the Jamui Hills in Bihar, flows through the western districts of West Bengal like Birbhum and Bardhaman, and eventually merges into the Bhagirathi-Hooghly system. Unlike tidal rivers, Ajay is not influenced by the tides of the Bay of Bengal, as it lies far inland and its flow regime is entirely seasonal. In contrast, rivers like the Hooghly, Ichamati, and Rupnarayan are located in the lower Gangetic delta, close to the coast, and experience tidal effects, including tidal bores and saline water intrusions, especially during high tides. These tidal rivers form part of the Sundarbans estuarine system, where tides regularly reverse the river current direction