What can the movement of constellations across Earth’s sky tell us about Earth’s movements?

It is evidence for the Sun’s revolution.
It is evidence for Earth’s rotation.
It is evidence for Earth’s rotation and revolution.
It is evidence for Earth’s revolution.

The caste system in india was used for what purpose? a) to ensure that all people had an adequate income b) to prevent the rich from taking too much power c) to provide social control and conformity according to one’s birth d) to draft a military capable of defending india from mongol invasion