下列何者是Fick’s Law？（PC: Partition coefficient；∆C: Concentration gradient；D: Diffusion coefficient；h: Thickness of skin barrier）
dQ/dt = D(PC) ∆C /h
dQ/dt = (PC) ∆C / D h
dQ/dt = D ∆C /(PC) h
dQ/dt = (PC) ∆C h / D
