An unlabeled hierarchical diagram of various astronomical bodies is shown below.

All planets have these same layers (From deepest to shallowest, inner core then the outer core, then the mantle, and lastly the crust. A good example is the Earth) that is shown in the diagram, even the sun has all the layers I just listed.
But, some planets I can think of are Mars, Venus, Moon, and the Earth of course.

Layer C. sounds like it could also represent Layer D, since they are so close.

P. S. I did my best to try to answer this.

Hola Amigo!! :D

The answer to you question is A. 

The Milk Way contains thousand of planetary systems. 

For Part 1:  I would choose A for Universe,  B for Milky Way,  C = Solar System  D-- Earth 

( A = Universe, B = Milky Way, C - Solar System, and D. Earth).

Part 2. You could choose any of which you choose for the planets such as Mercury, Venus, Mars, Jupiter, or a satellite.

Hope this helps!!

Have A Good Day!!

It has an alternating chemical phosphate and sugar backbone, making the 'sides' of the ladder. (Deoxyribose is the name of the sugar found in the backbone of DNA.) In between the two sides of this sugar-phosphate backbone are four nitrogenous bases: adenine (A), thymine (T), cytosine (C), and guanine (G).

Explanation: