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 30 year old female who had undergone a sugery under spinal anaesthesia has developed post spinal headache. How long does it take for the headache to subside? \nSelect and explain. \nA. Lasts up to 10 minutes, B. Last up to 4 days, C. Last up to 2 weeks, D. Last up to 2 months', 'role': 'user'}, {'content': "Answer: C \nExplanation: Post spinal headache usually begins after 48 hours and can last for 2 weeks. It can be minimised if CSF loss is minimised. Headache is usually dull in nature and is fron to temporal in location. Ref: Merritt's Neurology edited By Lewis P Rowland, page 382.", 'role': 'assistant'}]