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: Social & Preventive Medicine
[{'content': 'Symmetrical distribution is seen? \nSelect and explain. \nA. Normal standard detion, B. Bimodal distribution, C. Skewed distribution, D. U-distribution', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., Normal standard detion", 'role': 'assistant'}]