The correct answer is option 2: 12th March, 1930. The Dandi March, also known as the Salt March or Salt Satyagraha, was a significant event in the Indian independence movement against British rule. It was led by Mahatma Gandhi as a protest against the British salt monopoly. The march began on 12th March, 1930 from the Sabarmati Ashram in Gujarat, India and concluded on 6th April, 1930 at the coastal village of Dandi. During the march, Gandhi and thousands of his followers walked over 240 miles to the Arabian Sea coast to make their own salt. This act of civil disobedience was a powerful symbol of resistance against the British colonial rule and played a crucial role in mobilizing public support for the independence movement.