Correct Option: C

Lothal, located along the Bhogava river, a tributary of Sabarmati, in the Gulf of Khambat in Gujarat, was the only port-town of the Indus Valley Civilisation. It had a basin with vertical wall, inlet and outlet channels which has been identified as a tidal dockyard. Lothal’s dock was the earliest known dock found in the world, equipped to berth and service ships.