This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nose and PNS, Subject name: ENT
[{'content': 'CSF rhinorrhoea is diagnosed by: \nSelect and explain. \nA. b2 macroglobulin, B. b2 transferrin, C. Thyroglobulin, D. Transthyretin', 'role': 'user'}, {'content': 'Answer: B \nExplanation: (b) b2 transferrin(Ref. Cummings, 6th ed., 807)b2 transferrin on electrophoresis is pathognomonic of CSF as this protein is present only in CSF.', 'role': 'assistant'}]