Which statement best describes the difference between diffusion and osmosis in passive transport across membranes?

• A. Diffusion only applies to gases, whereas osmosis only applies to ions.
• B. Diffusion requires a selectively permeable membrane, whereas osmosis can occur without a membrane.
• C. Diffusion moves substances from low to high concentration using ATP, whereas osmosis moves water from high to low concentration without ATP.
• D. Diffusion is the net movement of any particles down their concentration gradient, whereas osmosis is the net movement of water across a selectively permeable membrane toward the side with higher solute concentration.

Answer: (D)