Who of the following before becoming the President of India did not hold the office of Vice-President?

In case the post of President of India falls vacant, and there is no Vice-President also, who among the following would be the acting President?

Which one of the following President of India has been the Governor of Bihar?

Who among the following is not appointed by the President

Who among the following Chief Justices of India also acted as the President of India?

Which one of the following statements about the President of India is not correct?