In which year the Planning Commission of India was established?

15 March, 1950

The correct answer is option (1) - 15 March, 1950

The Planning Commission was set up on 15 March 1950 by a simple resolution of the Government of India.
The Prime Minister was its Chairperson.
It was an extra-constitutional and non-statutory body.
It became the most influential & central machinery for deciding what path & strategy India would adopt for its development.
It had an advisory role and its recommendations became effective only when the Union Cabinet approved these.