In the context of passive transport, which statement best defines osmosis?

• A. The bulk movement of fluid and dissolved materials driven by pressure differences through a tissue or vessel
• B. The movement of solute molecules across a membrane from a region of lower solute concentration to a region of higher solute concentration without energy input
• C. The diffusion of water across a selectively permeable membrane from a region of lower solute concentration to a region of higher solute concentration
• D. The transport of ions across a membrane using ATP to move them against their concentration gradients

Answer: (C)