This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: FMGE 2019, Subject name: Anaesthesia
[{'content': 'The duration of spinal anaesthesia is based directly on: \nSelect and explain. \nA. Dose, B. Height, C. Age, D. Total body fat', 'role': 'user'}, {'content': 'Answer: A \nExplanation: The duration of spinal anesthesia depends upon the dose The level and duration is directly based on dose of the drug', 'role': 'assistant'}]