Correct answer: A. Sanskrit drama
Explanation: The correct answer is A, Sanskrit drama. Bhasa is traditionally regarded as one of the earliest important Sanskrit dramatists. Several plays are attributed to him, including Svapnavasavadatta, Pratijnayaugandharayana, and dramas based on episodes from the Mahabharata and Ramayana traditions. His works are valued for their lively plots, dramatic presentation, and treatment of well-known characters. The other options refer to different fields: medicine is associated with classical medical traditions, economics with texts such as the Arthashastra, and town planning with archaeological and administrative evidence. Therefore, Bhasa’s recognized literary field is Sanskrit theatre and drama.