With reference to the life of Vardhamana Mahavira, consider the following statements:

I. He was born at Kundagrama near Vaishali in the Vajji confederacy.

II. He attained Kevalya after twelve years of severe penance on the banks of river Rijupalika.

III. He delivered his first sermon at Sarnath.

IV. He attained Nirvana at Pavapuri.

Which of the statements given above are correct?