The Cripps Mission of 1942 was an attempt by the British government to secure Indian cooperation and support for their efforts during World War II.

Option 1 is incorrect as it was not a specific condition stipulated by the Cripps mission that all Indian states should join the Indian Union for consideration of any degree of autonomy.

Option 2 is correct. The mission proposed the creation of an Indian Union with Dominion status following the end of the Second World War. Dominion status refers to the semi-independent polities under the British Crown. This proposition reflected Britain`s willingness to grant India some degree of independence after the war.

Option 3 is incorrect as it is slightly misconstrued. While British did seek Indian cooperation for the war effort, it did not promise `full sovereign status` after the war, but dominion status.

Option 4 is incorrect. The mission did not explicitly mention the framing of a single constitution for the entire Indian Union, and requiring acceptance of this constitution by all provinces.

The correct answer captures the key aspect of the Cripps Mission, which was the offer of a dominion status to India after the end of World War II.