This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Physiology
[{'content': 'A substance is present in concentration of 2 mgdeg/o in the afferent aeriole and zero mg% in the efferent. True about the substance is: \nSelect and explain. \nA. It is free filtered in glomerulus, B. Secreted in coical nephron, C. Absorbed in PCT, D. Impermeable in loop of Henk', 'role': 'user'}, {'content': 'Answer: A \nExplanation: A i.e. It is freely filtered in glomerulus If the substance is 0 mg% in efferent aeriole, it means that all of it has freely filtered in glomerulus.', 'role': 'assistant'}]