Who was the Prime Minister of India when the basic principle of India's Nuclear Doctrine of 'No First Use' was adopted?

Who was the first Deputy Prime Minister of India?

The Prime Minister of India is responsible to whom?

Who among the following had the shortest span in office as the Prime Minister of India?

Who among the following held the office of the Prime Minister of India more than once?

If the Prime Minister of India belongs to the Upper House of Parliament: