Answer:
Moon, solar system, galaxy, universe
Explanation:
As of general information about astronomy, we know that moon revolves around earth, and earth revolves around sun, whereas sun makes up our solar system, which is the part of our galaxy milky way. There are groups of galaxies which makes cluster and combination of these clusters make cosmic web which is spread in the fabric of space-time in our universe.
So obvious facts are,
Universe is largest in this scenario
Combination of galaxies make clusters and clusters make universe. So, galaxies are smaller than universe.
One galaxy contains billions of stars. Our sun is just one star of billions in milky way galaxy, so obviously stars are smaller than a galaxy.
Our earth is part of solar system and moon revolves round earth, so moon is the smallest in this scenario. So correct answer is
Moon, solar system, galaxy, universe
