Find the odd one out regarding the Citizenship Act :
1) If he has been ordinarily resident in India for five years immediately before the commencement of the Constitution, he became a citizen of India.
2) A person who migrated to India from Pakistan became an Indian citizen if he or either of his parents or any of his grandparents was born in undivided India.
3) A person who migrated to Pakistan from India after March 1, 1947, but later returned to India for resettlement could become an Indian citizen.
4) A person who, or any of whose parents or grandparents, was born in undivided India but who is ordinarily residing outside India shall become an Indian citizen
When did the Ministry of External Affairs was created?