Explanation:

4th option is correct.
Simon Commission, group appointed in November 1927 by the British Conservative government under Stanley Baldwin to report on the working of the Indian constitution established by the Government of India Act of 1919.
On 11 September 1930, the personnel of the Round Table Conference were announced. The conference was opened officially by King George V on November 12, 1930 in London.
The Gandhi–Irwin Pact was a political agreement signed by Mahatma Gandhi and the then Viceroy of India, Lord Irwin on 5 March 1931 before the second Round Table Conference in London.
The Communal Award was made by the British Prime Minister Ramsay MacDonald on 16 August 1932 granting separate electorates in India for the Forward Caste, Lower Caste, Muslims, Buddhists, Sikhs, Indian Christians, Anglo-Indians, Europeans and Untouchables (now known as the Dalits) etc.