Analyze the effect of a concentration ratio (Q) equal to 1 on the spontaneity of membrane diffusion for uncharged molecules.

• A. Diffusion is non-spontaneous and occurs from low to high concentration.
• B. Diffusion is at equilibrium and no net movement occurs.
• C. Diffusion is spontaneous and occurs from low to high concentration.
• D. Diffusion is spontaneous and occurs from high to low concentration.

Answer: (B)