The correct option is C 1 November 1956
The State Reorganization Act, 1956 came into effect 1st November 1956. The act recommended organization of boundaries of the states based on linguistic lines. State Reorganization Commission was appointed by PM Jawaharlal Nehru in December 1953 and the commission submitted its report on 30 September 1955. The report's recommendations were debated in Indian parliament and later bill was passed to amend constitution.