Explanation:

- Harshavardhana (Option 2): Hiuen Tsang, also known as Xuanzang, visited India during the reign of Harshavardhana in the 7th century. Harsha was a prominent ruler in Northern India known for his benevolent governance and support of Buddhism and learning.

- Chandragupta I (Option 1): Chandragupta I was the founder of the Gupta Empire, ruling in the early 4th century. His reign predates Hiuen Tsang's visit.

- Samudragupta (Option 3): The son of Chandragupta I, he was a significant ruler of the Gupta dynasty, known for military conquests in the 4th century—not the period of Hiuen Tsang's visit.

- Chandragupta Vikramaditya (Option 4): Another great Gupta ruler, reigning in the late 4th to early 5th century. Hiuen Tsang's visit occurred much later.