Arrange the following events in chronological order and select the correct answer from the codes given below:
I. Maharaja Hari Singh signed the Instrument of Accession.
II. Constitution of India was enforced.
III. Accession to India ratified by the Sovereign Constituent Assembly of Jammu and Kashmir.
IV. New Constitution of the State of Jammu and Kashmir came into force.

1. A.I, III, IV, II
2. B.III, IV, I, II
3. C.I, II, III, IV
4. D.IV, III, II, I