Explanation:

The annual session of the Congress was held at Lahore in December 1929. During this session presided over by Jawaharlal Nehru the Congress passed the Poorna Swaraj resolution. Moreover, as the government failed to accept the Nehru Report, the Congress gave a call to launch the Civil Disobedience Movement.
After the Indian National Congress authorized Gandhiji to start Civil Disobedience Movement, he placed 11 Point Ultimatum to Irwin (31 Jan 1930) for administrative reforms and stated that if the Ultimatums are ignored, the only way out was civil disobedience. Gandhiji also informed of his decision to undertake Dandi Satyagraha wherein the laws of the government would be violated. Breaking the salt laws of the government non–violently was the basic activity of civil disobedience. Along with this activity, activities like no tax campaign, no revenue and no rent (land tax) campaign became very popular in different parts of India.
The 11 points ultimatum of Gandhiji to Lord Irwin after being ignored by the British Government made Gandhiji to launch the civil disobedience moment on 12th March 1930 with his famous Dandi March. (From Sabarmati Ashram to Dandi on Gujarat coast). On 6th April, Gandhiji reached Dandi, picked up a handful of salt and broke the salt law as a symbol of the Indian people’s refusal to live under British made laws and therefore under British rule.