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
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: 
Select and explain. 
A. It is free filtered in glomerulus, B. Secreted in coical nephron, C. Absorbed in PCT, D. Impermeable in loop of Henk
A: It is free filtered in glomerulus
Answer: A: It is free filtered in glomerulus 
Explanation: 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.