The correct statement about the Gandhi-Irwin Pact of 1931 is:
The Congress agreed to take part in the Second Round Table Conference.
The Gandhi-Irwin Pact was an agreement signed on March 5, 1931, between Mahatma Gandhi, the leader of the Indian National Congress, and Lord Irwin, the then Viceroy of India. As per the agreement, the Indian National Congress agreed to suspend the Civil Disobedience Movement and participate in the Second Round Table Conference in London. In return, the British government agreed to release political prisoners who had not been involved in acts of violence and to allow peaceful picketing of liquor and foreign cloth shops.