Correct answer: D. 3 June 1947
Explanation: The Mountbatten Plan was announced on 3 June 1947 by Lord Mountbatten, the last Viceroy of British India. It proposed the division of British India and set out the immediate framework for transferring power. For this reason, the date is closely associated with the Partition plan and is often called the 3 June Plan. Therefore, option D, 3 June 1947, is correct. The date should not be confused with 15 August 1947, which is the date India became independent, not the date on which this plan was announced.
The other dates are also unrelated to the announcement. 26 January 1950 marks the commencement of the Constitution of India, while 2 October 1947 is associated with Gandhi’s birth anniversary and was not the announcement date of the plan. The historical sequence is therefore clear: announcement on 3 June 1947, legal enactment through the Indian Independence Act in 1947, and independence in August 1947. Since the question asks for the exact date, option D is the precise answer.