Fort William in Kolkata is situated on the banks of the river:

Fort William stands on the eastern bank of the Hooghly river in Kolkata, West Bengal. The Hooghly (also called the Bhagirathi-Hooghly) is a branch of the Ganga.

History of Fort William:

• The original Fort William was built by the English East India Company between 1696 and 1706 and named after King William III of England.
• It was captured by Siraj-ud-Daulah, the Nawab of Bengal, in 1756, leading to the "Black Hole" incident.
• After Robert Clive's victory at the Battle of Plassey (1757), the British built a new, much stronger Fort William between 1758 and 1781, in the Maidan area.
• Calcutta became the capital of British India and remained so until 1911.

Fort William today:

• It is the headquarters of the Eastern Command of the Indian Army.
• Fort William College, set up in 1800 by Lord Wellesley, trained British officials in Indian languages and helped develop modern Hindi, Urdu and Bengali prose.

About the Hooghly river:

• It branches off from the Ganga in West Bengal and flows south through West Bengal for about 260 km to the Bay of Bengal.
• Kolkata, Howrah, Chandannagar, Serampore and Haldia lie on its banks.
• It is a tidal river, with tides felt up to well above Kolkata.
• Its major tributaries include the Damodar and the Rupnarayan.

Bridges over the Hooghly in Kolkata:

• Howrah Bridge (Rabindra Setu): a cantilever bridge opened in 1943.
• Vidyasagar Setu: a cable-stayed bridge opened in 1992.
• Vivekananda Setu and Nivedita Setu.

Ports:

Kolkata Port (Syama Prasad Mookerjee Port) is India's only major river port and its oldest operating port. Haldia Dock lies downstream.

European settlements on the Hooghly:

The Portuguese at Hooghly-Chinsurah, the Dutch at Chinsurah, the French at Chandannagar, the Danes at Serampore and the English at Calcutta.

Why not the other options?

• ✗The Ajay and Rupnarayan are rivers of the Hooghly system, not the river at Kolkata itself.
• ✗The Mahananda flows through north Bengal and Bihar.