Correct Answer:
B. 1955
The One Unit Scheme in Pakistan was established in 1955. This administrative policy aimed to merge the four provinces of West Pakistan (Punjab, Sindh, NWFP, and Balochistan) into a single province, creating parity with East Pakistan (now Bangladesh). The primary objective was to simplify governance, reduce regional disparities, and foster national integration. The scheme remained in effect until 1970. 1947 marks Pakistan's independence, 1962 saw a new constitution, and 1971 was the year of East Pakistan's secession, making these options incorrect for the establishment of the One Unit Scheme.