Which of the following statements regarding the advisory jurisdiction of the Supreme Court is/are correct?

I. It is binding on the Supreme Court to give its opinion on any matter referred to it by the President. II. The full bench of the Supreme Court hears any reference made to it under its power of advisory jurisdiction. III. The opinion given by the Supreme Court on a reference under advisory jurisdiction is not binding on the government. IV. Not more than one reference at a time can be made to the Supreme Court under its power of advisory jurisdiction.