The correct answer is A. Charyapadas.
Charyapadas are Buddhist songs composed in the 8th to 12th centuries in Assamese language. They are written in a simple and lucid style and are full of devotional fervor. The songs are mostly about the life and teachings of the Buddha and his disciples. They are also a valuable source of information about the social and cultural life of Assam during that period.
B. Kotha Ramayana is an Assamese version of the Ramayana epic. It was composed by Madhava Kandali in the 14th century. The work is written in the champu style, which is a mixture of prose and verse. It is a popular work of Assamese literature and is often recited during religious festivals.
C. Drona Parva is a section of the Mahabharata epic. It tells the story of Dronacharya, the teacher of the Pandavas and Kauravas. The section is full of battles and intrigues. It is one of the most popular sections of the Mahabharata.
D. None of the above is a Buddhist song composed in the 8th to 12th centuries.