Explanation:

• Gandhi-Irwin Pact in London, agreement signed on March 5, 1931, between Mohandas K. Gandhi, leader of the Indian nationalist movement, and Lord Irwin (later Lord Halifax), British viceroy (1926–31) of India. It marked the end of a period of civil disobedience (satyagraha) in India against British rule that Gandhi and his followers had initiated with the Salt March (March–April 1930). Hence option 1st is correct.