Correct Answer: Megasthenes

Solution : The correct answer is Megasthenes.

Megasthenes, a Greek diplomat and historian, served as an ambassador to Chandragupta Maurya's court in Pataliputra on behalf of Seleucid king Seleucus I Nicator. His lost work, the Indica, offered valuable insights into ancient Indian culture. Although the original text is lost, scholars have reconstructed it using later literary sources, shedding light on the lives of ancient Indians during Chandragupta Maurya's rule.