Question

An unlabeled hierarchical diagram of some astronomical bodies is shown. The labels A, B, C, and D can be used to represent galaxies, solar system, clusters, universe, and planets.

Part 1: Which four astronomical bodies would you choose to represent the four labels in the diagram?
Part 2: Justify your choice based on the hierarchical relationships in astronomical bodies.

Answer 1

As the picture shows, D is the smallest while A is the largest so, 
A: Universe
B: clusters 
C: Galaxy
D: Solar System

Part 2:
This is because the universe contains all of the galaxies,  a cluster is defined as a group of galaxies, a galaxy is a collection of solar systems and a solar system is a collection of stars, planets, comets and other bodies. 

Answer 2

A: Universe

B: Clusters

C: Galaxy

D: Solar Systems

I put it in this order because D is smaller and darker and rounder like a planet. D is the solar system because it contains the planets. C is the galaxy because it holds all of the billions and trillions of stars. B is clusters because the universe is contained with all the other galaxys. A is the universe because it contains the galaxy, the stars in the galaxy, the solar system, the planets in the solar system, and the all other galaxys.