Which of the following organisation was replaced by the NITI Aayog?

The correct answer is Option 2: Planning Commission

NCERT: On 1 January 2015, the NITI Aayog was formed. India adopted centralised planning after its Independence, but subsequently, it graduated into decentralised multi-level planning. The responsibility of plan formulation was with the Planning Commission at the Centre, State and district levels. But on 1 January 2015, the Planning Commission was replaced by the NITI Aayog. NITI Aayog has been set up with the objective of involving the states in economic policy-making for India for providing strategic and technical advice to the Central and State governments.