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: Dental
[{'content': 'Non parametric test used to compare the medians of two independent samples \nSelect and explain. \nA. t-test, B. Chi square test, C. Mann Whitney U test, D. Z test', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]