I believe your answer is A “changing and developing”
Good luck!
If it isn't using energy, it's called diffusion
Fluorine has 9 protons and 9 electrons
Iodine has 53 protons and 53 electrons
The digestive system takes the nutrients from the food you eat as well as the water. The leftover matter is excreted through the body as feces, or poop. Hope I helped :)