This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Renal physiology, Subject name: Physiology
[{'content': 'Filtration barriers have pores, which have size about \nSelect and explain. \nA. 1-2 nm, B. 4-6 nm, C. 8-10 nm, D. 10-12 nm', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Filtration barrier has pore size of about 4-6 nmRef: Ganong&;s review of medical physiology; 24th edition; page no; 673', 'role': 'assistant'}]