Correct option is A
Under State Re-organisation Act 1956 the former part ‘C’ State of Ajmer, Abu Road, Taluka, the former part of princely state, Sirohi which was amalgamated in former Bombay and Sunel Tappa area of the former Madhya Bharat fused with Rajasthan. The Sironj subdistrict, Jhalawar was relocated to Madhya Pradesh
Hence, According to State Re-Organisation Act 1956 , on 1 November, 1956 State Rajasthan finally formed.