The leaders of the Persian Empire worked to show tolerance for all religions. But one religion became prominent during the reign of . This religion was founded by . He taught that life is a struggle between good and evil. A person could earn a reward in heaven by .

Persian Empire leaders worked to show tolerance for all religions.  But one religion became prominent during the reign of Cyrus II. This religion was founded by Zarathustra. He taught that life is a struggle between good and evil. A person can earn a reward in heaven by avoiding evil and doing good.

Explanation:

When Cyrus II defeated the Astíages, he assumed the leadership of the Persian empire. At the time, he adopted Zoroastrianism, a religion founded by the prophet Zarathustra and made it the most influential religion in the region, although it allowed religious freedom and was tolerant in comparison to people who did not want to adopt Zoroastrianism. This religion was dualistic and proved that life was a constant struggle between good and evil and people who overcame evil by doing good things would be rewarded with paradise. This religion was very influential and had its downfall during Islamist invasions.

i believe your answer is d)