Which of the following was an achievement in the field of astronomy during the gupta empire

No option provided, however,
One of the important developments in the field of astronomy was a theory proved by Aryabhatta that the earth is round in shape unlike the ancient belief that it is flat. The theory of gravity was also promulgated by the astronomers of the Gupta empire. They also proved that the earth revolves around its own axis.
He believed that the Earth’s orbit is elliptical and not circular.