The correct answer is option 4: 27th December, 1911 in Calcutta. On this day, the Indian National Congress held its annual session in Calcutta (now Kolkata). During the session, the poet Rabindranath Tagore had composed the song "Jana Gana Mana" which was later adopted as the National Anthem of India. Tagore recited the song for the first time at the session, and it was sung by the audience. The National Anthem was officially adopted by the Constituent Assembly of India on 24th January, 1950, which is why options 1 and 2 stating the year as 1950 are incorrect. Option 3 stating 26th December, 1942 is also incorrect as it does not align with the historical records of the event.