On what condition did Mahatma Gandhi and Jawaharlal Nehru promise Congress' support to the Britishers in the second world war?

They promised Congress support to the war effort if the British in return, promised to grant India independence once hostilities ended.

The correct answer is Option 4 - They promised Congress support to the war effort if the British in return, promised to grant India independence once hostilities ended.

In 1935 a new Government of India Act promised some form of representative government. Two years later, in an election held on the basis of a restricted franchise, the Congress won a comprehensive victory. Now eight out of 11 provinces had a Congress “Prime Minister”, working under the supervision of a British Governor. In September 1939, two years after the Congress ministries assumed office, the Second World War broke out. Mahatma Gandhi and Jawaharlal Nehru had both been strongly critical of Hitler and the Nazis. Accordingly, they promised Congress support to the war effort if the British, in return, promised to grant India independence once hostilities ended. The offer was refused. In protest, the Congress ministries resigned in October 1939. Through 1940 and 1941, the Congress organised a series of individual satyagrahas to pressure the rulers to promise freedom once the war had ended.