If astronomers watch the stars all night, they have to keep moving their telescopes as the stars seem to move across the sky. Why does this happen?

D)

Explanation:

The main reason as to why stars seem to move like planets in the night sky is because of our Earth. The Earth is rotating on it's axis as well as revolving around the sun at the same time. Therefore turning once around us every 24 hours, which to us makes it seem as though the starts are moving like the rest of our planets do around the sun.