_____ was an ambassador who was sent to the court of Chandragupta by the Greek ruler of West Asia.
Megasthenes
The question refers to a Greek ambassador who was sent as an envoy to the Mauryan court of Chandragupta Maurya at Pataliputra.
Megasthenes was despatched by Seleucus I Nicator, the Greek (Hellenistic) ruler of West Asia and a former general of Alexander, following the treaty between Seleucus and Chandragupta.
During his stay Megasthenes observed Mauryan administration, society and the capital city, and recorded his observations in a famous account known as the 'Indica', which survives only in fragments quoted by later writers.
His writings are an important foreign source for the history and society of the Mauryan period.
The other names belong to much later travellers: Al-Biruni came with Mahmud of Ghazni in the 11th century, Marco Polo was a 13th-century Venetian traveller, and Ibn Battuta was a 14th-century Moroccan traveller who visited the Delhi Sultanate.
None of these three had any connection with Chandragupta Maurya, whose reign belongs to the 4th century BCE.
Therefore the answer is Megasthenes.
Who among the following travelers visited India in the 7th century CE?
The Greek historian Megasthenes visited India during the reign of which Indian ruler?
Megasthenes was an ambassador who was sent to the court of which Indian ruler by the Greek ruler of West Asia Seleucus Nicator?
In travel through India Fahien has mentioned a hospital. It was located at
Hien Tsang came to India from which country?
How many sub-committees have been mentioned by Magasthenes to conduct military activities in the Mauryan administration?