The correct option is (b).
Explanation: Indika was written by Megasthenes, a Greek ethnographer and explorer in the Hellenistic period. He was the ambassador of Seleucus I of the Seleucid dynasty to Chandragupta Maurya in Pataliputra.
The Arthashastra is an ancient Indian treatise on statecraft, economic policy and military strategy, written in Sanskrit by Chanakya.