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: Anaesthesia
[{'content': 'A 20 year old man complain of headache after spinal anaesthesia. Which of the following is the likely cause? \nSelect and explain. \nA. Raised ICT, B. Meningitis, C. CSF leak, D. Encephalitis', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Here the headache is believed to be due to loss of CSF. It can be minimised by using a smaller bone needle.', 'role': 'assistant'}]