(a) Aryabhatta was a great astronomer.

Aryabhatta an Indian mathematician and astronomer is known for his findings that earth revolved on its axis. He also invented the magic number Zero.

(b) Stories about gods and goddesses are found in the Puranas.

Puranas means old. They contain stories of gods, goddesses and kings.

(c) Valmiki is recognized as the author of the Sanskrit Ramayana.

Ramayana, a story of Lord Ram was written by Valmiki. It is one of the most popular books of ancient India.

(d) Silappadikaram and Manimekalai are two tamil epics.

Epic means long stories. Silappadikaram is about the love of a wife towards his husband. These epics remained lost for hundreds of years.