This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Excretory System (Kidney, Bladder) Acid-Base Balance, Subject name: Physiology
Albumin appearing in urine will be due to- 
Select and explain. 
A. It is of small size, B. Increase in GFR, C. Loss of charge in glomerulus, D. None of the above
C: Loss of charge in glomerulus
Answer: C: Loss of charge in glomerulus 
Explanation: The molecular diameter of the plasma protein albumin is only about 6 nanometers, whereas the pores of the glomerular membrane are thought to be about 8 nanometers (80 angstroms). Albumin is restricted from filtration, however, because of its negative charge and the electrostatic repulsion exeed by negative charges of the glomerular capillary wall proteoglycans.