Answer:
C. Osmosis
Step-by-step explanation:
Osmosis is the net movement of solvent molecules, usually water, from a region of lower solute concentration to a region of higher solute concentration through a partially permeable membrane. Osmosis is a very useful for moving materials in and out of the cell.
Solutions are mixtures of solutes and solvents. The main aim of osmosis is for all the mixture part to be uniform and the solvent equally dispersed to all the part of the solution.
Osmosis is controlled to a large extent by concentration gradient.
Diffusion on the otherhand is the movement of molecules of a substance from one position to another.
Facilitated diffusion and active transport are just mechanisms for transport within a cell or a body.