Exp) Option a is the correct answer.

The judges of the Supreme Court are appointed by the President. The Chief Justice is appointed by the President after consultation with such judges of the Supreme Court and high courts as he deems necessary.

Statement 1 is incorrect: The President (not Parliament) can appoint a judge of the Supreme Court as an acting Chief Justice of India when the office of Chief Justice of India is vacant. This can also happen when the Chief Justice of India is temporarily absent; or Chief Justice of India is unable to perform the duties of his office.

Statement 2 is incorrect: There is no such provision for the appointment of a retired Chief Justice of India as current Chief Justice of India by the President at any time. At any time, the Chief Justice of India can request a retired judge of the Supreme Court or a retired judge of a high court (who is duly qualified for appointment as a judge of the Supreme Court) to act as a judge of the Supreme Court for a temporary period. He can do so only with the previous consent of the President and also of the person to be so appointed.

Statement 3 is correct: Additional Judges can be appointed by the President under Article 224 of the Constitution. The President can only appoint duly qualified persons as additional judges of a high court for a temporary period not exceeding two years when: there is a temporary increase in the business of the high court; or there are arrears of work in the high court When the need for this arises, the State Government should first obtain the sanction of the Central Government for the creation of such additional posts.