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': 'All are non-parametric tests except - \nSelect and explain. \nA. Chi-square test, B. Sign test, C. Fisher exact test, D. Student t-test', 'role': 'user'}, {'content': "Answer: D \nExplanation: Ans. is 'd' i.e., Student t-test", 'role': 'assistant'}]