Correct option is B
· On January 26, 1950, the Constitution became operative.
· The First Five-Year Plan was then introduced on 1 April 1951, after the Planning Commission had been established on 15 March 1950. This five-year plan was based on Harrod- Domer model of USSR.
· The long-term plans of the Indian government to develop and organise the economy with effective resource usage are referred to as economic planning.
· After gaining independence in 1950, economic planning in India began when it was decided that it was essential for the country's development and economic prosperity.