Gandhi gave his speech before starting out on the 'Salt March' on the banks of which river?

Sabarmati

The correct answer is Option (2) → Sabarmati

People gathered on the banks of the Sabarmati River to hear Mahatma Gandhi speak before starting out on the Salt March in 1930.

The Salt March:

Gandhiji had given advance notice of his “Salt March” to the Viceroy Lord Irwin, Irwin failed to grasp the significance of the action. On 12 March 1930, Gandhiji began walking from his ashram at Sabarmati towards the ocean. He reached his destination three weeks later, making a fistful of salt as he did and thereby making himself a criminal in the eyes of the law. Meanwhile, parallel salt marches were being conducted in other parts of the country. As with Non-cooperation, apart from the officially sanctioned nationalist campaign, there were numerous other streams of protest. Across large parts of India, peasants breached the hated colonial forest laws that kept them and their cattle out of the woods in which they had once roamed freely. In some towns, factory workers went on strike while lawyers boycotted British courts and students refused to attend government-run educational institutions. As in 1920-22, now too Gandhiji’s call had encouraged Indians of all classes to make manifest their own discontent with colonial rule. The rulers responded by detaining the dissenters. In the wake of the Salt March, nearly 60,000 Indians were arrested, among them, of course, Gandhiji himself.

The Salt March was notable for at least three reasons. First, it was this event that first brought Mahatma Gandhi to world attention. The march was widely covered by the European and American press. Second, it was the first nationalist activity in which women participated in large numbers. The socialist activist Kamaladevi Chattopadhyay had persuaded Gandhiji not to restrict the protests to men alone. Kamaladevi was herself one of numerous women who courted arrest by breaking the salt or liquor laws. Third, and perhaps most significant, it was the Salt March which forced upon the British the realisation that their Raj would not last forever, and that they would have to devolve some power to the Indians.