Final answer:
During the Mauryan dynasty, Buddhism was a popular religion that was replaced by Hinduism during the Gupta dynasty.
Step-by-step explanation:
During the Mauryan dynasty, Buddhism was a popular religion. The religion that replaced it during the Gupta dynasty was Hinduism. The Mauryan Empire, founded by Chandragupta Maurya, witnessed the rise of Buddhism as an alternative to Hinduism. However, after the collapse of the Mauryan Empire, the Gupta dynasty established Hinduism as the official religion of the state, while also allowing the flourishing of Buddhism and other religions.