When did the Government of India replaced the Planning Commission with a new institution named "NITI Aayog".

1 January 2015

The correct answer is option (4) - 1 January 2015

The Government of India replaced the Planning Commission with a new institution named NITI Aayog. NITI Aayog stands for National Institution for Transforming India. The NITI Aayog came into existence on 1 January 2015. The Prime Minister was its Chairperson. At that time Shri Narendra Modi was the PM of India. Thus, he became the first chairperson of the NITI Aayog. The Vice-Chairperson of NITI Aayog is appointed by the Prime Minister of India.