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': 'Chi square test is applied to test the independence of cross distribution of two variables and each of them should have \nSelect and explain. \nA. Equal number of cases, B. Mutually exclusive cases, C. Normal distribution, D. Non-mutually exclusive cases', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]