Answer:
A
Step-by-step explanation:
It's passive transport because it does not require energy, i.e. you don't need to invest ATP to make it happen. Osmosis is the movement of water from area of higher solute concentration to area of lower solute concentration. It happens via channel proteins called aquaporines. Simple diffusion is when gases like O2 or CO2 difuse through the cell membrane. Again, they go from area of higher concentration to area of lower concentration. Facilitated difusion is how large and polar molecules go in and out of the cell. This happens via transmembrane proteins down the concentration gradient (from higher to lower concentration).