The correct answer is option 3: 24th January 1950. The Constituent Assembly of India adopted the National Anthem on this day. The National Anthem of India is called "Jana Gana Mana" and was composed by Rabindranath Tagore. It was first sung on 27th December 1911 during the Indian National Congress session in Kolkata. The complete version of the National Anthem was adopted by the Constituent Assembly on 24th January 1950, which was three days before the Indian Constitution came into effect on 26th January 1950. The National Anthem is a symbol of national identity and is sung or played on various occasions, including the beginning of official and public functions in India.