The correct answer is option 2 - The president can make an ordinance only when either of the two Houses of Parliament is not in session. This is a provision given in the Constitution of India (Article 123) which empowers the President to promulgate Ordinances when either of the two Houses of Parliament is not in session, and hence it is not possible to enact laws in the Parliament.

Option 1 is incorrect because the Planning Commission, an executive body, was not accountable to the Parliament.

Option 3 is incorrect as there is no minimum age for becoming a judge of the Supreme Court in the Indian constitution. However, it does state that a Judge of the Supreme Court must have been a judge of a High Court or of two or more such Courts in succession for at least five years or an advocate of a High Court or of two or more such Courts in succession for at least ten years.

Option 4 is incorrect because not only Union Finance Minister and the Chief Ministers of all states, Prime Minister is the head of the National Development Council. This council also includes members of the Planning Commission (now NITI Aayog) which further includes the Cabinet Ministers.