Megasthenes, the Greek ambassador to the Mauryan court, wrote a detailed account of India in his work titled:

The correct answer is: a) Indica.

Megasthenes was a Greek ambassador to the court of Chandragupta Maurya, the founder of the Mauryan Empire in India. He wrote a detailed account of India in his work titled Indica. Indica is a valuable source of information about ancient India, and it is one of the earliest surviving accounts of the country by a foreign visitor.

The other options are incorrect. Arthashastra is a treatise on statecraft and economics written by Kautilya, a Brahmin minister in the court of Chandragupta Maurya. Mudrarakshasa is a play about political intrigue written by Vishakhadatta in the 6th century CE. Mahabhashya is a commentary on Panini’s grammar written by Patanjali in the 2nd century BCE.