Right choice is (a) Physiologic model
Easy explanation: Physiologic models are made with the assumption that the drug movement within a body region is much more rapid than its rate of delivery to that region, this assumption will be applicable to highly membrane permeable drugs i.e. drugs with low molecular weight, nonionized and lipophilic drugs. For highly polar, ionized and charged drugs, the model is referred to as membrane permeation rate-limited.