The correct answer is option 2, the August Offer of Viceroy Linlithgow. The August Offer, also known as the Linlithgow Declaration, was made in August 1940 by the Viceroy of India, Lord Linlithgow.

In this declaration, Lord Linlithgow recognized that the framing of the new Constitution for independent India should primarily be the responsibility of the Indians themselves. However, he also stated that the British government would still have a role in the process and would work towards granting dominion status to India after the war.

Option 1, the Government of India Act, 1935, is incorrect because although it did introduce certain reforms and provided for the establishment of a federal structure in India, it did not explicitly concede that the framing of the new Constitution should be primarily the responsibility of Indians.

Option 3, the Cripps Proposals, is also incorrect. The Cripps Proposals, made by Sir Stafford Cripps in 1942, were an attempt to resolve the political deadlock in India and gain Indian support for the British war effort. The proposals offered limited self-government to India, but they did not explicitly concede that the framing of the new Constitution should be primarily the responsibility of Indians.