The correct option is B January 26, 1950
The Constitution of India came into force on 26 January 1950. The Constitution Assembly set up a Drafting Committee under the Chairmanship of Dr. B. R. Ambedkar on 29 August, 1947 to prepare a Draft Constitution for India. The Constitution of India was adopted by the Constituent Assembly on 26 November 1949 and came into force on 26 January 1950.