The answer is D. The digestive system provides energy to your muscular system by breaking down foods and using those nutrients to create energy. It is like how when you are starving, you feel weak because you don't have energy. When you eat something you get more energy so you can move
The youngest would be the ones at the top and the oldest would be at the bottom. the oldest is B and the ones around it, as they get bigger get younger. hope this helps :)
Does not have a nucleus. The prokaryotic cell's chromosome float around the cell itself.
