In India, Jainism spread during the reign of which of the following King?

Chandragupta Maurya

The correct answer is Option 3- Chandragupta Maurya

Jainism spread during the reign of Chandragupta Maurya.

Chandragupta Maurya was the founder of the Mauryan Empire, which ruled over much of India in the 4th and 3rd centuries BCE. He was a contemporary of Mahavira, the last Tirthankara of Jainism.

Chandragupta Maurya is said to have been deeply influenced by Jainism. He is said to have become a Jain monk in his later years and to have died by performing the Jain ritual of sallekhana (fast unto death).

Chandragupta Maurya's patronage of Jainism helped to spread the religion throughout India. He built many Jain temples and monasteries, and he supported Jain monks and scholars.