The correct option is A Gandhiji started the march from Sabarmati Ashram to Dandi on 12 March 1929.
In the 1880s, the British had passed the Salt Act, which prohibited Indians from collecting or selling salt. Indians were forced to buy salt from the British, who levied a heavy salt tax. Gandhi Ji wrote to Lord Irwin regarding this oppressive measure. But Lord Irwin was not willing to negotiate on the demands put forth by Gandhi. On 12 March 1930, Gandhiji set out on a march from Sabarmati Ashram to Dandi. The march initially started with 78 of his trusted followers and was joined by thousands of others during the journey. Gandhi Ji and his followers covered 240 miles and on 5 April 1930 reached Dandi. On the morning of 6 April 1930, Gandhiji evaporated seawater to make his own salt, and by doing so, he broke the Salt Law.