(D) The second Five-year Plan(1956–1961) laid emphasis on development of the public sector and ‘rapid Industrialisation’.The plan followed the Mahalanobis model, an economic development model developed by the Indian statistician Prasanta Chandra Mahalanobis in 1953. The plan attempted to determine the optimal allocation of investment between productive sectors in order to maximise long-run economic growth. It used the prevalent state of art techniques of operations research and optimisation as well as the novel applications of statistical models developed at the Indian Statistical Institute.