The correct answer is option 4, the Mountbatten plan.

The Mountbatten plan, also known as the June 3rd Plan, was formulated by Lord Mountbatten, the last Viceroy of India, in June 1947. This plan proposed the partition of India and the creation of two separate nations, India and Pakistan. The decision to partition Punjab and Bengal was to be taken on the basis of voting by the Members of the respective Legislative Assemblies.

Option 1, the Nehru report, is not correct as it was a constitutional proposal presented by the Indian National Congress in 1928. It did not specifically address the partition of Punjab and Bengal.

Option 2, the Cripps mission plan, is not correct as it was a proposal put forward by Sir Stafford Cripps in 1942 for India`s participation in the Second World War. It did not deal with the partition of Punjab and Bengal.

Option 3, the Beveridge report, is not correct as it was a landmark social welfare report published in 1942 in the United Kingdom. It had no direct relevance to the partition of India.

Therefore, the correct answer is option 4, the Mountbatten plan, as it specifically addressed the partition of