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': 'The standard normal distribution \nSelect and explain. \nA. Is skewed to the left, B. Has variance = 1.0, C. Has standard deviation = 0.0, D. Has mean = 1.0', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Normal Distribution:\n\nIs also known as ‘Gaussian distribution’ or ‘Standard distribution’\nType of distribution: Is the distribution of values of a quantitative variable such that they are symmetric with respect to\xa0a middle value with same mean, median and mode, and then the frequencies taper off rapidly and symmetrically on\xa0both sides – ‘bell shaped distribution’.', 'role': 'assistant'}]