This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Kidneys and Body Fluids, Subject name: Physiology
In renal disease albumin is first to appear in urine because 
Select and explain. 
A. Of its high concentration in plasma, B. Has molecular weight slightly greater than the molecules normally getting filtered, C. High albumin : globulin ratio, D. Tubular epithelial cells are sensitive to albumin
B: Has molecular weight slightly greater than the molecules normally getting filtered
Answer: B: Has molecular weight slightly greater than the molecules normally getting filtered 
Explanation: Ans. (b) Has molecular weight slightly greater than the molecules normally getting filtered(Ref: Ganong, 25th ed/p.677)Glomerular membrane permits neutral substances up to 4 nm in diameter. Substances greater than 8nm diameter are totally excludedAlbumin size is 7 nm. So, it has molecular weight slightly greater than the molecules normally getting filtered