The Quit India Movement was launched by Mahatma Gandhi on:

The Quit India Movement, also called the August Kranti (August Revolution), was the last major mass movement of the freedom struggle led by Mahatma Gandhi.

The background was the Second World War. India had been dragged into the war without the consent of Indian leaders. In March 1942, the British government sent the Cripps Mission, led by Sir Stafford Cripps, to win Indian support. It offered dominion status after the war, but not immediate independence, and was rejected. Gandhi described it as "a post-dated cheque on a crashing bank". Meanwhile, Japan was advancing through South-east Asia towards India.

On 14 July 1942, the Congress Working Committee at Wardha passed a resolution demanding that the British quit India. On 8 August 1942, the All India Congress Committee met at the Gowalia Tank Maidan in Bombay (now called August Kranti Maidan) and passed the Quit India Resolution. In his speech, Gandhi gave the famous call "Do or Die" ("Karo ya Maro").

Early in the morning of 9 August 1942, the British arrested Gandhi and almost all the top Congress leaders under "Operation Zero Hour". Gandhi was kept in the Aga Khan Palace in Pune, where his wife Kasturba and his secretary Mahadev Desai died. With the leaders in jail, the movement became leaderless and spontaneous. People attacked symbols of British authority, such as railway stations, police stations and post offices. Leaders such as Jayaprakash Narayan, Ram Manohar Lohia and Aruna Asaf Ali organised underground activities. Aruna Asaf Ali hoisted the Congress flag at Gowalia Tank on 9 August. Parallel governments were set up in Ballia, Tamluk and Satara.

9 August is observed as August Kranti Day.

Why not the other options?

• ✗9 August 1942 is the date of the leaders' arrests and the start of mass action.
• ✗26 January 1930 was celebrated as Purna Swaraj Day.
• ✗12 March 1930 is when the Dandi March began.