Who was Megasthenes?

Option 1 -> Megasthenes served at Chandragupta Maurya's court (c. 302 BCE), the founder of the Mauryan Empire.

Option 2 -> Samudragupta was a Gupta dynasty ruler (4th century CE), lived centuries after Megasthenes.

Option 3 -> Bindusara was Chandragupta's son and successor, ruled after Megasthenes' time at the court.

Option 4 -> Ashoka was Chandragupta's grandson, ruled much later than Megasthenes' visit.

Hence, Option 1: A Greek ambassador to the court of Chandragupta Maurya -> Megasthenes was sent by Seleucus I Nicator to Chandragupta Maurya's court at Pataliputra. He wrote "Indica," a valuable account of Mauryan India, though the original is lost and known only through later references -> correct