Which Statement Regarding Diffusion of Gases Is True

Which statement regarding diffusion of gases is true?

A) The rapid rate of diffusion of O₂ in water makes respiration more efficient in water-breathing than in air-breathing animals.
B) Respiratory surfaces in mammals have a thin fluid film to improve diffusion of gases.
C) In the lungs, extracellular fluid speeds the movement of O₂ into cells.
D) The slow rate of diffusion of O₂ in water limits efficiency even in air-breathing mammals.
E) Exchange of respiratory gases in an insect in which air is carried in tracheoles to air capillaries is less efficient that in a fish gill where there is a countercurrent flow system.