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.

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.

b is the correct answer