Correct Answer: (b) Iran
Note: According to a definition given about the Aryans: The Indo-Iranian group whose members composed the Zoroastrian scriptures, the Hindu scriptures such as the Veda, called themselves Aryans. So it is clear that in the Vedic period it was the region of present-day Iran, where Zoroastrianism prevailed, and the 'Avesta' was written by Zoroastrian.