The molecules doesn't need energy to cross through.
The diffusion doesn't need protien, the molecules pass between phospholipids by passes protien. It moves smaller molecules. Facilitated need protien also hormone, and larger molecules.
I wish it makes sense.
I believe the first answer is #4 and the second is #1. Please correct me if I am wrong.
The third answer because I was taught this information
The answer is: It keeps you Hydrated