Correct Option: A

Pataliputra, the ancient city of Patna in Bihar, served as the capital city of the Mauryan empire. It reached the pinnacle of prosperity under Chandragupta Maurya and Ashoka. Greek ambassador, Megasthenes, has left a detailed account of its splendor. Pataliputra was
originally built by Magadha ruler Ajatsatru in 490 BC.