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': 'True about post spinal headache \nSelect and explain. \nA. Frontal, B. More in lying down, C. Low incidence with thin (25 G) needle, D. Increased by abdominal compression', 'role': 'user'}, {'content': 'Answer: C \nExplanation: C i.e. Low incidence with thin needle', 'role': 'assistant'}]