Answer:
A
Explanation:
There are different mechanisms for transport of molecules across the cell membrane. One kind of this transport is facilitated diffusion, this is a form of passive transport, not requiring any ATP (the opposite would be active transport, where it does require ATP.
Simple diffusion does require special transport proteins, and neither does osmosis. Filtration is a technique used for sterilisation of water, where any impurities can be drawn out of the liquid
