The correct chronological order of the Prime Ministers in India is option 3: II, I, III, IV.

Option 1 (I, II, III, IV) is incorrect because it places Indira Gandhi as the first Prime Minister instead of Jawaharlal Nehru.

Option 2 (II, III, I, IV) is also incorrect because it places Morarji Desai before Indira Gandhi, which is incorrect as she served as Prime Minister between Nehru and Desai.

Option 4 (III, II, IV, I) is incorrect because it puts Charan Singh as the last Prime Minister, whereas he was actually the fourth Prime Minister in the given order.

Therefore, the correct chronological order is option 3 (II, I, III, IV) with Jawaharlal Nehru being the first Prime Minister, followed by Indira Gandhi, Morarji Desai, and Charan Singh.