According to Fick's Law,which Event Would Cause a Decrease in the Rate

According to Fick's law,which event would cause a decrease in the rate of diffusion?

A) A decrease in the size of the respiratory membrane (A)
B) A decrease in the distance (L) between the two surfaces
C) An increase in the partial pressure difference of the gas at its two locations (P₁ - P₂)
D) An increase in the size of the respiratory membrane (A)
E) None of the above