National anthem was adopted by the Constituent assembly on .

The Indian National Anthem The Constituent Assembly of India approved Jana-gana-mana, a Bengali song written by Rabindranath Tagore, as the National Anthem of India on January 24, 1950.

It was initially performed at the Indian National Congress's Kolkata session on December 27, 1911.

Hence, the correct answer is option A, i.e., 24 January 1950