The correct option is A Declaration of August 20, 1917
As the First World War continued, and the Home Rule League was gaining momentum, the leaders of the Congress and the League impressed upon the British Government that their demands for constitutional reforms should not be rejected if they wished Indians to be loyal to the British. The Government, therefore, felt it necessary to pacify the Indians by the Declaration of August 20, 1917, which promised a policy of gradual development of self-government institutions in India.