Explanation:

- Hiuen Tsang: A famous Chinese Buddhist monk and scholar. He traveled to India to study Buddhism and collect religious texts. His journey was significant for cultural and religious exchanges between China and India.

- Option 1: Ashoka

- An Indian emperor of the Maurya Dynasty.

- Reigned from 268 to 232 BCE.

- Famous for spreading Buddhism, but he ruled much earlier than Hiuen Tsang's time.

- Option 2: Vishnugupta

- Also known as Chandragupta II, was a Gupta emperor.

- Incorrect timeline for Hiuen Tsang's visit.

- Option 3: Samudragupta

- A prominent ruler of the Gupta Empire.

- Known for his military conquests.

- Reigned before Hiuen Tsang's time.

- Option 4: Harsha

- Reigned from 606 to 647 CE.

- Known for his patronage of arts and Buddhism.

- Hiuen Tsang visited India during his rule.

- Correct Answer